OBSCURA OSPRO
Settings

Guides

How this actually works, checked rather than asserted.

Every one of these was written by checking it. The field names, the byte offsets and the arithmetic in them came from reading the formats and from building files and looking at what was actually in them, and anything that could not be checked was left out and said so. Each ends at the tool on this site that does the thing, and every one of those runs in your browser with nothing uploaded.

Recently written

An Adobe Audition alternative for podcasts, in your browserWritten 7 October 2026. OBSCURA Sound edits, cleans up and sets the loudness of a podcast in a browser tab, with nothing uploaded. What it does, and where Audition is the better choice. An Audacity alternative that keeps the recording on your computerWritten 7 October 2026. OBSCURA Sound is a multitrack audio editor in a browser tab, with noise reduction and podcast loudness. Where Audacity, which is free, is the better choice. An Affinity Designer alternative that runs in your browserWritten 7 October 2026. OBSCURA Vector draws in a browser tab with nothing to install and no account. Affinity is free; this says honestly when to use it instead, and when Vector fits. An Adobe Illustrator alternative that runs in your browserWritten 7 October 2026. OBSCURA Vector draws with the pen, shapes, type and pathfinder in a browser tab, with SVG and PDF out and nothing uploaded. Where Illustrator is the better choice. Family tree software without Ancestry: keeping the tree yourselfWritten 7 October 2026. Keep the master copy of your family tree on your own device, not in an Ancestry or MyHeritage account: getting the GEDCOM out, what stays behind, and Roots. A RootsMagic alternative that runs in your browserWritten 7 October 2026. RootsMagic is a mature desktop genealogy program for Windows and Mac. Roots keeps the tree on your device too, in a browser tab, with GEDCOM in and out.

Is it safe to send or upload this?

What is on the document besides the part they asked for, who needs which part of it, and what happens to a copy once it has left you.

Is it safe to upload a file to a free online tool?It depends much less on the tool's promises than on one fact: the moment you upload, the file is a copy on somebody else's computer, and every…Start here Is it safe to send a scan of your passport or driving licence?What the image is worth to a thief, which fields to black out for which purpose, why the watermark convention works, and why a redaction website is the worst place to prepare one. Is it safe to upload your CV, and what is it giving away?What to leave off, what a Word CV says about its author, and the hidden-text problem, including the copy you did not put there. Is it safe to upload your bank statement?It depends who is asking, and “use a secure connection” answers the wrong question. Why you must not redact one for a lender, what a letting agent is actually entitled to, and what the PDF carries that is not printed on it. Is it safe to upload your payslip?Everything written about payslips and privacy is about whether a company may email them to staff. What is on yours besides the pay (the National Insurance number, and every deduction by name), and who is entitled to see it. Is it safe to send a medical letter or test result?Everything written about this is aimed at clinics, and none of it binds you as the patient. Who actually needs the whole letter, what is in it besides the clinical part, and why the letterhead is half the disclosure. What you hand over when you paste into an AIFive ordinary things people paste into a chat box, scanned: 3,125 characters, 26 findings, and 16 of them a live credential or a card number. What a screenshot gives awayNo GPS and no camera data: the metadata answer is short and reassuring. The risk is the tabs, the notification, the email in the corner and the session token in the URL bar. Plus why blurring text does not work. Is it safe to upload a utility bill as proof of address?A proof-of-address check reads your name, address, the supplier and a date. What else is on the bill, and which numbers to remove before you upload it.

What is in a file that you did not put there

The location in a photo, the author in a document, the text under a redaction and the dots a printer adds: what each format carries, and where.

Does a photo show where it was taken?Usually yes, to about a third of a metre. A photograph from a phone normally carries the latitude and longitude of the spot it was taken, the time… EXIF, IPTC and XMP: which one is in your photo?Three standards written by three different authors, and the same fact stored in all three. What it means when they disagree, and why a photo with no GPS can still name the street. Does a PNG Have GPS or EXIF in It?It can, and it usually does not: PNG had no way to hold EXIF at all until 2017. Which chunk each thing lives in, and why converting to PNG is not the way to strip a location. Why a cropped photo still shows what you cropped outA JPEG carries a second, complete picture inside its EXIF block, written when the shutter fired. Nothing in the format obliges an editor to redraw it when you crop, so the file you send can still hold the frame you removed. What a video file gives away about youThe camera, the operating system version, the editor and the moment to the second, and on an iPhone, often not one location but a reading every second or so for the length of the clip. Which of it a metadata strip removes, which it cannot, and why the picture itself usually gives away more. What is hidden in a Word documentA .docx is a zip archive full of XML, and the words on the page are only one part of it. Data still in a spreadsheet you deletedAn .xlsx is a zip archive of XML parts, and deleting something from the grid changes one part and leaves the rest. Can text under a PDF redaction be recovered?Usually, yes, and it takes no skill: select the blacked-out area and copy it, or open the file with anything that extracts text. What you hand over when you forward a meeting inviteThe whole attendee list, the organiser, the dial-in PIN buried in the description, and a join link closer to a key than an address. What is in an .ics, and how to send one without it. Does your printer hide tracking dots on every page?Most colour laser printers and copiers put pale yellow dots on every page that name the machine and the date. How to see them on a page of your own, what can be read, and what taking them out of a scan does and does not protect. Is there a message hidden in this image?Three places to look, in the order they are actually used, and most of what gets found is a file stuck on the end, not anything clever in the pixels. Why the standard statistical test misses the commonest case, and the four things it cannot see at all. What is actually in a Google Takeout exportA maze of product folders with everything interesting buried in JSON files nobody expects you to open. The location history alone has five different shapes, the files are too large for a text editor, and uploading the zip is the one thing not to do. Change the date a photo says it was takenThe date taken is an EXIF field inside the JPEG, separate from the file's created and modified dates. Which field to change, the time zone, and how to do it.

Keeping who you are out of it

A face, a voice, a writing style, a front door on a running route, a name in a spreadsheet: what identifies a person once the obvious part is gone.

Can your writing style identify you?Yes, on a few hundred words, from the words you never choose: function words, punctuation and sentence rhythm. What stylometry sees, the cases people know, which habits can be flattened and which only you can change. Can you make a voice unrecognisable by changing the pitch?Partly, and less than you think. It defeats a stranger, not somebody who knows you, and one number undoes it. What the shift moves and everything it leaves exactly where it was. How to blur faces, plates and screens out of a photo without uploading itWhy pixelation beats a blur, what else in the frame identifies people, and what the saved copy still carries. Share a run or a ride without giving away where you liveA GPS track starts and ends at your door, with the time on every point, and a privacy zone hides that on one site only. How much to cut, why the times matter, and how to trim the file itself. How to anonymise a spreadsheet without losing who is whoFind and Replace is not consistent across a second file and a lookup table is the re-identification key written down. A keyed hash does both jobs, and why a plain hash is not anonymous. How to check a dataset is safe to publish, and why removing the names is not enoughPostcode, date of birth and sex identify most of a population on their own. What k-anonymity measures, what generalising costs, and why a comfortable k can still give the whole answer away. What a website learns about you before you clickBefore you click anything, a site has your IP address and the handful of headers every request carries. What utm_source and fbclid on a link actually doCampaign tags and click identifiers are two different things wearing the same clothes. How to tell if an email has a tracking pixelMost pages on this are written for senders who want to add one. How to find the pixel in a message you received, what it reports, and what actually stops it.

Was this changed, and is it genuine?

Hashes, signatures, saved revisions and edit histories: what each can show about a file, and the point where each stops being able to tell.

Was this file changed?Hashes, signatures, a PDF's saved versions, a photo's edit history and the marks a cut leaves: what each shows about a file, and where each one stops.Start here How to check a file has not been changedTake the SHA-256 of the file you have and compare it, character for character, with the value the publisher gave you. Was this PDF changed after it was signed?A signature covers a stated range of bytes, not the whole file, so anything appended afterwards leaves it verifying perfectly. What matters is not whether the file grew but what was added. What a PDF keeps after you delete a pageA PDF can be saved by appending, so the deleted page, the removed comment and the pre-redaction text are all still in the file and the reader just hides them. How to tell if a photo has been editedEverybody says check whether Software says Photoshop, which is the weakest signal in the file. The edit history XMP keeps, the three dates that disagree, the thumbnail that no longer matches, and what none of them can tell you. Was this audio recording edited or spliced?Four traces a cut leaves behind and how to measure them without uploading the file, and why a lossy re-encode destroys all four, so finding nothing proves nothing. How to work out the time of day from a shadow in a photoThe ratio of a shadow to its object gives the sun's height and its direction gives the bearing, and both are computable for any place and date. A worked example with the two windows it produces, the claim tested against them, and the four things that can be wrong when they disagree. How to tell if an email is really from who it saysIgnore the From line: it is text the sender typed, and nothing in delivery checks it. What is smime.p7s? The attachment on a signed emailIt is the email's signature, not a document. What is inside it, what a valid signature proves and what it does not, why mail programs call one invalid, and how to check it with OpenSSL or in a browser tab. How to check an SSH key fingerprint, and what to compareOne command prints it. The part that matters is comparing it with a fingerprint that reached you by another route, what the two SSH warnings are really telling you, and how to audit an authorized_keys file. A decision log, and why the reasons in it matter more than the decisionsNobody is asked two years later whether a decision was right. They are asked what was known, what else was considered and when it was written down. What a hash chain does and does not prove.

A file that will not open, or comes out wrong

HEIC, .msg, winmail.dat, a .docx without Word, a CSV in one column, a zip Windows refuses, and pages that move or shrink on the way to the printer.

Opening a file without the software that made itMost files that will not open are a container your machine has no reader for. HEIC, .msg, winmail.dat, Word, Excel, zips and CSVs, opened in the browser tab.Start here How to open a HEIC file, and turn it into a JPEGA photograph in a container most software cannot open: what the box is, what is inside it, and how to get a JPEG out without uploading it. Open a Word document without Word, and without uploading itA .docx is a zip of XML a browser can read. Open it, change it, and save it back as Word or as PDF in the tab; what comes across, and what does not. How to open an Excel file without Excel, and without uploading itAn .xlsx is a zip of XML a browser can read in the tab. What comes across (sheets, values, formulas, formats), what does not (charts, macros, pivot tables), and how to save it back. How to open a .msg file without Outlook, and without uploading itA .msg is a small file system, not text, which is why only Outlook opens one. Reading it in a browser tab, saving the attachments, keeping the headers, and why a converter site sees everything on it. How to open winmail.dat on a Mac, iPhone or anywhereThe attachments you were sent are inside it, packed by Outlook in a format nothing else reads. Getting them out without installing an app or uploading the email, and the one setting on the sender's side that stops it. Why your .docx opens as XML, and what to doA Word file is a zip of XML, so the markup is not itself a fault. Four different problems look like this and their fixes have nothing in common, starting with whether the file is a Word document at all, which its first bytes say and its extension does not. Why your CSV opens in one column, and how to fix itA CSV does not record its own separator, so Excel guesses from a Windows regional setting rather than from the file. How to tell which yours uses, three fixes, and the conversions a spreadsheet performs silently once the columns do split. Why Windows will not open your AES-encrypted zipThe file is not corrupt and the password is not wrong. File Explorer implements only the 1989 encryption scheme; yours uses the 2003 one, and Windows 11 did not change that. How to tell which you have, and three ways to open it. Why a zip says the path is too longError 0x80010135 is a 260-character limit in the Windows API, not a damaged archive: the same file opens everywhere else. How to find which name inside yours is the long one, what the registry setting does and does not cover, and how to take the files out without recreating any folders at all. Why Word page numbers change on another computerThe pages are not in the file; every machine lays them out again, and a substituted font moves every break after it. Which references hold, and how to give a transcript page and line numbers that do. Why a print comes out smaller than actual sizeFit to page, the wrong paper size, the browser's own scale, and the driver's printable area: four settings that shrink a print by 94 to 97 per cent without saying so. Print a 100 mm ruler and the number it reads names the culprit. How to print a booklet on an ordinary printerThe imposition rule written out, why it is always a multiple of four, why you flip on the short edge, and what a signature is for. Why a PSD opens blank or white outside PhotoshopA layered PSD saved with Maximise compatibility off holds a white placeholder where the picture should be. Why viewers show it, and how to see the real image. Why Excel cuts off columns when you save as PDFExcel saves a PDF the way it prints: page by page, inside the print area. Five causes of missing columns, how to tell which you have, and the setting for each. “The file is damaged and could not be repaired”: what it means for a PDFWhat Acrobat's damaged-file error means, how to tell a cut-off download from a file that was never a PDF, and how a PDF's index can be rebuilt. Why only the first page of a TIFF shows, and how to see the restA multi-page TIFF stores each page as its own image, and many viewers stop after the first. Which programs show them all, and how to turn one into a PDF. Change an image to 300 dpi without losing qualityDPI is a number in the file's header, not a property of the pixels. What 300 dpi means for print size, when to change the label, and when the picture is too small. Open a Canon CR3 raw file on WindowsCR3 is Canon's raw format since 2018. The free Windows extension that shows it, Canon's own software, the JPEG hidden inside every CR3, and converting one. Why a PDF table comes out wrong in ExcelA PDF has no table in it, only words placed on a page. Why converted tables land in one column, split or merge wrongly, and how to get a usable sheet. Why a PNG converted to SVG looks bad, and how to get a clean oneConverting a PNG to SVG is tracing: guessing shapes from pixels. Why the result has jagged edges, blobs and a huge file, and what to feed a tracer for a clean one. Why a DXF opens at the wrong scale, and how to fix itA DXF stores bare numbers, and $INSUNITS is the only place it says what they mean. How to read it, why 25.4 is the usual error, and how to fix the file. Why an STL is the wrong size in the slicer, and how to fix itAn STL has no units: it is a list of bare numbers, and the slicer assumes millimetres.

Locking it, signing it and handing it over

Passwords that hold, the kind of PDF and zip password that protects nothing, signatures and what each proves, and sending a file without a server keeping it.

How to make a password you can actually rememberPick the words at random from a published list instead of inventing a password yourself. A free password manager with no account and no cloudWhat a vault is underneath, what you get by having no account, and the four things you give up, starting with sync and ending with recovery. How to password protect a PDF, and which password protects nothingA PDF can carry two passwords and only one is security. What AES-256 does, why an owner password stops nobody, and what removing a password can and cannot mean. How to password protect a zip file, and what it still gives awayTwo kinds of zip password, one broken since 1994. Why Windows will not open the good kind, and what the file names tell anyone holding the archive. How to sign a PDF without uploading it, and which signature you needAn image, an electronic signature with an integrity record, and a certificate-based digital signature are three different things. Which one you are being asked for. How to send a file without it sitting on a serverEncrypt it to the recipient's public key, or hand it over directly between two browsers. Unprotect an Excel sheet when you have lost the passwordSheet protection is a flag in plain XML, not encryption, so it comes off your own workbook without the password. A password to open is different, and cannot. Make an SSH key on a Chromebook, with or without LinuxWith ChromeOS's Linux environment, ssh-keygen is one command. Without it, on a school or work Chromebook, how to make a key and use it with Secure Shell or GitHub. A 1Password alternative with no account and no copy on a server1Password keeps an encrypted copy of your vault on its servers. Keep holds passwords, codes and papers on your device, kept in step through your own folder. A Bitwarden alternative that keeps the vault off every serverBitwarden has a free plan, is open source and audited, and syncs through a server. Keep is paid, and keeps passwords and papers on your device with no server. How to convert a 1Password .1pux export to CSVA .1pux is your whole vault, unencrypted, in a zip. What is inside it, which managers import it directly.

A suspicious file, a device or a network

Checking a PDF, an extension or a QR code before trusting it, and reading captures, DNS logs, connection logs and USB history for what they show.

How to check a PDF for malware without uploading itEvery answer to this says upload it to VirusTotal, which shares what you upload. What a browser can read instead (scripts, actions that run on open, embedded files, and every address the document points at), and why finding nothing settles less than it seems. What a browser extension can do, before you install itEvery answer tells you to read the box Chrome shows when you click Add. The extension is a zip you can download and read first, and it names the SDKs and the addresses the dialogue never mentions. What a QR code can hide, and how to check oneA QR code is text and nothing more, and the danger is not in the square but in the fact that a person cannot read it before acting on it. How to see what a device on your network connects toEvery answer tells you how to list the devices on your network; none tells you what they talk to. Four ways to capture traffic from a device you cannot install anything on, what a capture still reveals when everything is encrypted, and the check that tells you whether a privacy setting did anything. How to read a pcap file without WiresharkWhat a pcap and a pcapng actually contain, the five questions worth asking of a capture first, and how to answer them in a browser tab (conversations, DNS, the server name in a TLS handshake, credentials in the clear, flows on a timer) without uploading a file full of secrets. How to spot malware beaconing in a connection logSearching for a fixed interval finds nothing, because every implant since about 2013 adds jitter for exactly that reason. The three scale-free measurements that survive it, how they hand the configured sleep and jitter back, and why no tool can tell you which beacon is the malicious one. How to find generated domains in a DNS logScoring each name for randomness gives you ninety alerts a day, almost all wrong, until somebody switches it off, and it never sees the families built from dictionary words. The evidence is in the hundreds of names one machine was told did not exist. How to tell if a USB drive was plugged into a PCWindows writes every device install into a plain text file, with the vendor, product and serial number. What a line really means (first attachment, not a usage count), and the generated serial that reads exactly like a match across two machines and is not one. Sorting files by hash, and why a broken algorithm is still the right one hereMost files on any machine are identical to millions of others and can be eliminated in seconds. Why that needs three algorithms at once, and the difference between a collision attack and a preimage attack. What a Windows prefetch file shows, and what it does notA .pf proves a program ran: the last eight run times, a run count, the files it loaded and the volumes it read.

Getting the number right

Averages, charts, samples, dates, units, coordinates and timestamps: the arithmetic that looks settled and has two answers, and how to tell which one you have.

Why a bar chart has to start at zeroA bar says “this much” by its length, so a cut axis draws a different number. The distortion has no ceiling, and labelling the axis does not undo it. When the mean is the wrong average, and what to quote insteadThe mean is a balance point, so one large value drags it. Four ways to tell when it is misleading, and the one property only the mean has. Benford's law: when it finds invented numbers, and when it tells you nothingThe most misapplied result in auditing. Which columns the leading-digit test holds for, the five kinds it never will, the tests that need no assumption at all, and the threshold test that catches real splitting. Why a random sample needs a seed, and why the seed should be published“Randomly” is unfalsifiable in both directions. A seed turns the draw into something anybody can reproduce and check. Days between: two answers, both right, and the one that loses a deadlineMonday to Wednesday is two days or three, and clear days makes it one. Plus why adding a month to the 31st has two defensible answers. The units that are two different units with one nameTwo gallons, three tons, a fluid ounce that goes the other way, two miles, two mils and two kinds of calorie. Each has caused a real accident. How to convert coordinates between formats, and the misreading that puts you 700 metres outDegrees and decimal minutes read as degrees, minutes and seconds is up to 729 metres out and looks entirely reasonable. What a datum is, why a British grid reference needs OSTN15, and the UTM zones everyone gets wrong. What is this timestamp? How to decode a number when you do not know the formatSeventeen formats with their epochs and tick sizes, every one written as the same instant so the shapes can be compared, how to narrow a number down by digit count, and the thing a timestamp will never tell you. Why VLOOKUP doesn't match values that look the sameA trailing space, a number stored as text, an en dash, a letter O for a zero: eight invisible differences, how to prove which one it is in two cells, and what to do when the formula is fine and the lists genuinely disagree. Find the lowest cash balance in the month, not the closing oneIt can end the month in credit and still fail in week seven. Run the balance forward a week at a time, take the smallest number, and then ask how late the receipts can be before it reaches zero. How much can you discount before you lose money?Not the margin. A discount comes out of the contribution, so ten per cent off a forty per cent margin is a quarter of the profit on it and needs a third more units to stand still. The floor for the whole business, and the four levers compared. Why an Apple Health export adds up to too many stepsA phone and a watch both count the same walk, and the export keeps both. The three things in the file that count twice, and how to total it in a spreadsheet, in Python, or without code. Fuzzy name matching, and why a threshold of 50 catches nothing but noiseUnrelated names run as high as 59 on Jaro-Winkler while real spelling variants start around 85. Why the gap between those decides your threshold, and why equivalents, particles and initials matter more than the metric. Readability scores: what they measure, and the one thing they are good atThey cannot tell whether a sentence means anything, and writing to hit one makes prose worse. The sentence list is the output that matters. How the VIN check digit is calculated, worked throughThe ninth character of a North American VIN is a check digit. The letter values, the weights, a full worked example, and what passing the check does not tell you.

On site and at an incident

Slings, fall arrest clearance, levelling, stairs, tile orders, cordons, triage and rotas: the working that has to be right before anybody relies on it.

Why a four-leg sling is rated on three legsThe standard will not assume four legs are sharing, and that is the smallest of three reasons dividing a load by the number of legs gives an answer that is too low. What the angle really costs, and the sideways squeeze that appears on no sling chart and is what damages loads in transit. How much clearance you need below a fall anchorA two-metre lanyard needs 6.65 metres of clear space beneath you and a scaffold lift is two. The five-part stack that makes up the distance, why clipping low adds the drop twice, and why low-level work usually needs restraint rather than arrest. Rise and fall vs height of collimation, and the checkTwo routes to one answer on the same booking, the check that must come out equal three ways, the intermediate sight it cannot see, and a misclosure worked against the allowance and distributed across the setups. What a cordon costs, in perimeter and in peopleFour hundred metres is two and a half kilometres of line and twenty-six posts before anybody is relieved. Why stand-off tables give two distances. The triage sieve and START: four questions each, one real disagreementThey agree on almost every casualty and not on all of them. Plus the bookkeeping that actually fails at a multiple-casualty scene. Checking a rota: the rules are about the gaps, not the daysA late then an early is nine hours and looks fine in a grid. Why a calendar week hides the worst fortnight in most rotas ever written. How much extra tile to buy, and why small rooms need moreTen per cent is a rule of thumb for cuts and breakages. How to count the tiles a floor really needs, why a small room wastes more, and what to keep back. How many stairs for a 9-foot ceiling, worked outA 9-foot ceiling is not a 9-foot rise. Measuring floor to floor, the IRC's 7¾ inch riser and 10 inch tread, and why the usual answer is 16 risers and 15 treads.

Records, evidence and investigations

Chronologies, call records, association charts, reconstruction arithmetic, custody clocks and bundles: the record somebody will read closely later.

How to build a chronology when some dates are approximateMarch 2026 is not 1 March 2026. Five kinds of date, the rule that orders them without inventing a day, how a gap is measured so a vague date cannot manufacture one, and a six-event run worked through. How to keep a record of calls and letters about a disputeWrite it the same day, with both dates on it: when it happened and when the note was made. What a note of a call needs, why letters go in the same log, and why a late entry should say so. How to analyse phone call records and find the patternsFive questions, each one pivot: who, since when and until when, what hours, where the silences are, and who two people both talk to. The finding is usually a date, and the records never leave the machine. Reading a schedule of call data, and the two mistakes that do the most damageRead a month-first file as day-first and every event moves by up to eleven months with nothing looking broken. Why a cell site is not a location, and why one number can count as four. Association charts, and why counting links finds the wrong personThe person with forty connections is a switchboard. The one worth finding has three and sits on the only path between two groups, looking unimportant. Bridges, articulation points, and why a layout must be reproducible. How to work out speed from skid marks, and why the answer should be a rangeThe equations are undisputed; the measurements are not. Why a drag factor and a skid length entered as ranges give a band several miles an hour wide, and which equation is confidently wrong most often. Area of convergence from bloodstains, worked by handWidth over length for the angle, the long axes crossed for the convergence, and the tangent for the height. Nine stains worked, and why the height is a ceiling: quote the least of them, never the average. How the PACE detention clock works, and why it does not start at the arrestSection 41(2) gives four answers for when the clock starts, and every limit and review moves with it. The 24, 36 and 96 hour limits, why reviews run from the last one carried out, and how custody time limits differ. Writing an account of a use of force, and the four habits that cost mostA conclusion instead of a description, the passive voice, hindsight in the wrong paragraph, and the trade dialect heard outside the job as a euphemism. How to redact a PDF for discovery without uploading itA black box over text does not remove it. What real redaction, metadata review and chain of custody take, done in the tab. Bates numbering a bundle without uploading itEvery free Bates stamper asks you to upload the PDF, which for a disclosure bundle is the one thing you cannot do. What a Bates number is for, the prefix and padding that make a bundle sort into its own order, and what to check before it goes anywhere.

Doing the job without uploading it

Merging, compressing and converting PDFs, reading text out of a scan, transcribing, shrinking a photo, making a CV or an EPUB, all in the tab.

How to merge, split and reorder PDFs without uploading themPut several PDFs into one, take one apart, pull pages out, turn and reorder them, number the pages, in the tab. What happens to size and metadata, and what to do about a locked file. How to compress a PDF without uploading it, and what really shrinksA PDF is heavy because of its pictures, not its words. What downsampling, de-duplicating and tidying each save, which setting to pick, and the four kinds of file that will not shrink at all. How to turn a PDF back into an editable document, without uploading itA PDF has no paragraphs in it, only glyphs at coordinates. What a converter is really inferring, which parts come back and which do not, and why a scan gives you nothing. A free PDF editor that never uploads your fileFill a form, sign, write on a page, black something out, turn and reorder pages, and save, in the tab. What it does, what it does not, and which of the site's PDF tools does each job best. How to get the text out of a picture or a scan without uploading itWhat OCR reads well, what it reads badly, why handwriting does not work at all, and how to turn a scan into a PDF you can search. How to transcribe a recording without uploading it to anybodySpeech recognition in the tab: what a small model gets right, where it invents, and why an interview or a consultation should never be handed over. How to make a photo smaller without uploading it, and what size to pickA phone photo is four megabytes and the form wants one. The two settings that make it small without anyone noticing, JPEG against WebP against PNG, the iPhone's HEIC, and what happens to the location. Make an EPUB from a Word file without uploading itAn EPUB is a zip of web pages, and a browser can write one: chapters at the headings, a cover, the details a reader shows, and what to check before sending it anywhere. A free CV builder with no sign-up, watermark or uploadA form, three layouts, the page as it will print, and the CV out as a PDF or a Word file, made in the tab. What is there, and what is deliberately not.

Moving off a subscription

The office suite, the photo editor, the PDF service and the planner, each set against the product people leave, with what does not come across.

A free alternative to Google Docs, Sheets and Slides that needs no accountA word processor, a spreadsheet and a slide editor that open and write Word, Excel and PowerPoint, in the tab, with the files on your own disk. What is there, and the list of what is not, which starts with working together. A free PowerPoint alternative that runs in your browserEight layouts and a slide master, shapes, tables, transitions, speaker notes, a presenter view, and a .pptx opened or written in the tab. What is there, and what is not. A Photoshop alternative that runs in your browserLayers you can mask, adjustment layers you can reopen, selections by hand and by colour, editable text, and a project file that keeps all of it. What is there, and what is not. A free notes app that keeps your notes as files on your own diskA markdown notebook with links, backlinks, tags, a graph and daily notes, where every note is a plain .md file in a folder you choose. Why plain files, what is there, and what is not. A free Anki alternative that needs no account or installThe same SM-2 scheduler, cloze deletions and reverse cards in a browser tab, and the four things Anki has that this does not. A Smallpdf alternative that does the work in your browserCompress, merge, split, sign, protect, redact and convert, each Smallpdf job matched to a tool that never uploads the file, with what is free, what is Pro, and what is not here. An iLovePDF alternative that keeps the file on your computeriLovePDF's families of tools (organise, optimise, convert, edit and sign, security) done in the tab, family by family, with the cost of each and the gaps. A free Adobe Acrobat alternative for filling, signing and redacting PDFsComments, forms, signatures, pages, passwords and redaction that takes the words out of the file, free in the tab. What Acrobat does that this does not, starting with editing the existing text. A Photopea alternative with no adverts, that also runs in your browserBoth editors work on your own device. Where OBSCURA Photo Editor differs (no adverts, camera raw, CMYK proofing, part of Pro), and when there is no reason to switch. An ExifTool alternative with no command line, and no upload eitherExifTool's common jobs, command by command, in the tab: read what a photo carries, strip it, clean a folder, a video or a Word file. What ExifTool does that these do not. A free Trello alternative with no account, kept on your own deviceBoards, cards, checklists, labels, dates, automation rules and four views, with a Trello board brought over from its JSON export. The one thing it cannot do is share a board. A free Microsoft Project alternative with a real critical pathA Gantt chart, all four link types, calendars, resources, levelling, baselines and reports, with Project XML in and out. No .mpp, no hours, no shared plan. A Canva CV and resume alternative: a builder with no accountA form instead of a canvas: five layouts, a Plain one for application tracking systems, and a free PDF with no watermark, with the CV kept on your own device. A free Excel alternative with no accountA free spreadsheet in your browser with no account: formulas, charts and pivot tables that open and save as Excel .xlsx. What it keeps, and what Excel still does better. A tinkercad or onshape alternative that keeps designs on your computerParametric CAD in your browser with the designs kept on your own computer: how the Engineering Suite compares with Tinkercad and Onshape, and when each is the better choice. An AutoCAD LT alternative for 2D drawings in the browser2D drafting in the browser with AutoCAD's commands, ISO fits, GD&T, hatching, blocks, DXF and PDF to scale: how Foundry compares with AutoCAD LT, and when LT is the better choice. A CamScanner alternative with no account and no appYour phone probably has a document scanner built in already. What CamScanner's history means, the free scanners worth using, and scanning to PDF in a browser tab. A Relativity, Everlaw or Logikcull alternative for small firmsE-discovery for a small matter in your browser: load, dedupe, search, code, redact and produce with Bates numbers and DAT and OPT load files, with no upload and no per-gigabyte hosting. A Scrivener alternative that runs in your browserThe binder, corkboard, snapshots and compile in a browser tab, what comes across from a .scriv project, and when Scrivener is still the better choice. A Final Draft alternative for screenplays, in your browserThe industry’s script page, with .fdx and Fountain, in a browser tab, and the production tools Final Draft has that Write does not. An SPSS alternative that opens .sav files in your browserOpening .sav files and running the common tests with APA tables in a browser tab, and the statistics SPSS has that Research does not. An NVivo alternative for coding interviews on your own deviceCoding transcripts and survey answers, with queries and Cohen’s kappa, in a browser tab, and what NVivo does that Research does not. A QuickBooks alternative that keeps the books on your computerQuickBooks Online keeps your books on Intuit's servers. OBSCURA Books keeps them in your browser: bank statements, invoices, the VAT return and the year end. A Xero alternative for books kept on your own computerXero keeps a business's books in its cloud. OBSCURA Books keeps them in your browser, with no account: bank statements, invoices, the VAT return and the year end. A FreeAgent alternative for sole traders who keep their own booksFreeAgent files your Self Assessment and VAT with HMRC from its cloud. OBSCURA Books keeps the books on your computer and works the figures out, but does not file. A Clio alternative that keeps a firm's files on its own computerClio and LEAP keep a law firm's matters in their cloud. OBSCURA Practice keeps clients, conflicts, time, bills and client money on your computer, encrypted. A RootsMagic alternative that runs in your browserRootsMagic is a mature desktop genealogy program for Windows and Mac. Roots keeps the tree on your device too, in a browser tab, with GEDCOM in and out. Family tree software without Ancestry: keeping the tree yourselfKeep the master copy of your family tree on your own device, not in an Ancestry or MyHeritage account: getting the GEDCOM out, what stays behind, and Roots. An Adobe Illustrator alternative that runs in your browserOBSCURA Vector draws with the pen, shapes, type and pathfinder in a browser tab, with SVG and PDF out and nothing uploaded. Where Illustrator is the better choice. An Affinity Designer alternative that runs in your browserOBSCURA Vector draws in a browser tab with nothing to install and no account. Affinity is free; this says honestly when to use it instead, and when Vector fits. An Audacity alternative that keeps the recording on your computerOBSCURA Sound is a multitrack audio editor in a browser tab, with noise reduction and podcast loudness. Where Audacity, which is free, is the better choice. An Adobe Audition alternative for podcasts, in your browserOBSCURA Sound edits, cleans up and sets the loudness of a podcast in a browser tab, with nothing uploaded. What it does, and where Audition is the better choice.