Everything on OBSCURA OS
Every tool on the site, filed under what it is for. Every one of them runs in your browser, and the ones outside the Workspace are free to check a file with; saving the result is OBSCURA Pro. Nothing here uploads your files.
Workspace
Free, no account, and nothing is uploaded. Every one of them autosaves to your browser and exports to a real file you keep.
Applications11
DocsWrite and format documentsSheetsFormulas, several sheets, CSV and ExcelSlidesBuild a deckNotesMarkdown notes, linked togetherCalendarPlan without an accountTasksBoards of lists and cardsContactsAn address book with vCard import and exportPlanPlan a project and see the critical pathPDFOpen, fill, sign and edit a PDFDriveYour files, kept on this deviceTodayYour day, read from the other apps
Desk Suite 125 tools
The smaller tools that sit around the Workspace applications: a letter merged from a list, a calculator tape you can go back and edit, a rota checked against the rules it has to keep, a sheet of labels measured in millimetres.
Writing and notes8
MERGEOne letter per row, from a template and a listCVBuild a CV, out as PDF or WordOUTLINEAn outliner you drive from the keyboardPLAINFind the sentence your reader stops atHOUSESTYLECheck a document against your own style sheetSPEECHHow long a talk really is, section by sectionSCREENPLAYRead a Final Draft or Fountain script formatted, with scenes, cast and page countWORDCOUNTWords, manuscript pages and reading time, set against the usual lengths
Family history2
Numbers and money18
BASEA database you keep yourself, with typed columns and saved viewsCALCA calculator tape you can go back and editMONEYAccounts that reconcile, kept on this deviceCONVERTUnits, and the ones that are two units with one nameDATESDate arithmetic with the awkward parts namedZONESSee every city's clock side by side and find the overlapSPLITCut a CSV about without a spreadsheetLOANWhat a loan really costs, and what a flat rate hidesSETTLEWho owes whom, in as few payments as possibleBREAKEVENThe lever actually worth pullingRATECALCWork out the day rate you need from what you want to earn and what it costs youDESIGNRATEWhat graphic designers charge by the hour, the day and the projectCOPYRATEWhat copywriters charge by the hour, the day, the word and the projectILLUSRATEWhat illustrators charge by the day, the project and the licencePERMILEWhat your vehicle really costs a mile, and which tax method leaves you better offSEPCALCWork out the most you can put in a SEP IRA or solo 401(k) for 2026QTAXWork out your 2026 quarterly estimated tax, and catch up a missed oneCHECKDIGITCheck a card number, IBAN, ISBN, barcode or VIN by its check digit
Statistics and survey data6
FIGURESDescribe a column of numbers honestlySAMPLEDraw a random sample you can defendT-TESTRun a t-test on two groups, paired scores or one sample, from data or from means and SDsCHI-SQUARERun a chi-square test on a table of counts, with Fisher's exact test on a 2×2ALPHAWork out Cronbach's alpha, with item-total correlations and alpha if item deletedSAVOpen an SPSS .sav or .zsav file and see its data, variables and value labels
VAT and billable time3
Pictures and media5
Convert and make images15
VECTORTrace a picture into an SVG that scalesRASTERDraw an SVG as a PNG, JPEG or PDF at any sizeRAWTurn CR2, NEF, ARW and DNG raw files into JPEGsDPISet a picture to 300 dpi without re-saving itRETAGChange a photo's date, location and creditsDATAURITurn a picture into Base64 text, and backPSDOpen a Photoshop file and save its layers as PNGTIFFOpen a TIFF, and save its pages as JPEG, PNG or PDFANIMATETurn pictures into an animated GIF or PNGFRAMESCrop, resize, speed up, reverse or split a GIFMEMEPut top and bottom text on your own pictureCOLLAGEPut pictures side by side or in a gridGRIDCut one picture into a grid of piecesSKETCHTurn a photo into a pencil sketch or cartoonMOCKUPPut a screenshot in a browser or phone frame
Opening and converting files4
Office files3
Keys and certificates3
Reading and study4
PDF pages8
TRIMCrop the pages of a PDF, or trim the white margins offREFITChange a PDF's page size, or put two or four pages on a sheetMONOTONETurn a PDF black and white, keeping its text as textLIFTTake the pictures out of a PDF as JPEG and PNG filesCOLOPHONSee and change a PDF's title, author, dates and other propertiesBLANKSAdd text boxes, tick boxes and drop-downs to a PDF to make a formMENDRepair a damaged PDF that will not openFLATBEDTurn photos of pages into a clean scanned PDF
Convert to and from PDF8
PLATESTurn the pages of a PDF into JPG or PNG picturesTYPESETTurn a Word document into a PDFCOLUMNSTurn the tables in a PDF into an Excel spreadsheetSHEETFEDTurn an Excel workbook into a PDFHANDOUTTurn a PowerPoint deck into a PDFPROJECTORTurn the pages of a PDF into PowerPoint slidesTYPEWRITERMake a PDF from plain text, Markdown or a web pageBINDERYTurn an EPUB e-book into a PDF you can print or annotate
For people who build things8
REGEXWrite a regular expression and see what it doesFONTLENSRead what is inside a font, the licence includedSUBNETCalculate subnets, CIDR and VLSM for IPv4 and IPv6CRONExplain a cron expression and see its next run timesJSONFormat, validate, query and convert JSON in the browserRADIXProgrammer's calculator: hex, binary, octal and bitwiseIDENTGenerate and decode UUIDs and ULIDsJWKSVerify a JWT against a JWKS key set
Web and site owners3
Briefing and command9
BRIEFWrite a briefing that survives being passed onDEBRIEFRun a debrief that leaves actions behind itRISKAssess a risk and record what was known at the timeCHECKLISTRun a checklist and keep the proof you ran itHANDOVERHand over a shift without losing an itemSOPWrite a procedure somebody can actually followFormsQuestions and responsesINCIDENTWork an incident through its phases and keep the record as you goDRILLRehearse covert and evidence decisions in branching scenarios
Rotas, hours and people6
Charts and diagrams5
Printing and paper7
LABELSPrint a sheet of labels, measured in millimetresENVELOPEPrint an envelope, where the window isBOOKLETPut pages in the order a folded booklet readsBADGEName badges you can read across a roomPOSTEROne picture across several sheets of paperBARCODEA barcode that scans, at the size it will be printedPAPERGraph paper you can prove is to scale
Sovereign Suite 122 tools
Privacy and document-defence tools. Every one of them is free to check a file with.
All Sovereign tools on one page →
Photos and images10
CLOAKStrip metadata from a photoEXIFSee the GPS and camera data inside a photoVEILBlur faces and plates out of a photoSCREENSHIELDBlack out the private parts of a screenshotBASTIONArmor an ID scan before you send itTAMPERLook for signs a photo was editedSHRINKResize, convert and compress imagesIMAGEDIFFSee what changed between two imagesCONTRASTCheck colour contrast and find the nearest passing colourDOTSFind, read and remove a printer's hidden tracking dots
PDFs9
SEALRedact a PDF so it stays redactedPACTSign a PDF and keep a record that holds upFORMAUDITSee what a PDF runs and collectsFLATTENBurn a filled-in form into the page so it cannot be changedWATERMARKStamp a visible watermark across every pageSTAPLEMerge, split, reorder and number PDFsPADLOCKPut a password on a PDF, or take one off, on this devicePRESSMake a PDF smaller without sending it anywhereSTRATADig out every earlier version saved inside a PDF and see what changed
Documents and spreadsheets16
REDLINESee what changed in a contractCANARYFind out who leaked itSCRUBClean a document before you send itDISARMStrip macros, scripts and beacons from a documentBLINDDe-identify resumes for a fair reviewCLEANSHEETScrub hidden data from a spreadsheetMEDISCRUBRedact personal details from a recordDATASCANFind personal data hiding in a spreadsheetDOCSCRUBClean metadata and comments from a Word fileCALSCRUBClean a calendar invite before you share itDELTASee exactly what changed between two textsMACROLENSRead the macros in an Office file without running themNETTERMSChase an invoice that has not been paidTELLSSee the habits that identify your writing, and flatten themLANTERNFind text hidden for a machine to read and a person to missLINEAGERead the editing history a Word file keeps about itself
Email7
MAILBOXTake an email apart and see where it came fromHEADERPROOFCheck if an email is really from who it saysPHISHLENSCheck a suspicious email or link safelyUNBEACONRemove tracking pixels from an emailUNSUBFind the real unsubscribe link in an emailSATCHELOpen an Outlook .msg or a winmail.dat without OutlookDMARCBuild and check SPF, DKIM, DMARC and security.txt
Links, QR codes and the web7
SANILINKStrip tracking tags out of a linkCOOKIEAUDITSee which cookies are tracking youPOLICYLENSRead the fine print of a privacy policyQRSHIELDSee a QR code link before you tap itQRMAKERMake a QR code that stays on your machineRAMPARTCheck a site's security headers and Content-Security-PolicyAMBEROpen a Safari .webarchive on any computer or phone, and save it as one .html
Audio and video8
SCRIBETranscribe a recording to text on your deviceVOICEGUARDDisguise a voice by shifting its pitchSPLICELook for cuts and joins in a recordingRECASTBlack out part of a videoSNIPCut a piece out of a recordingREELRecord your screen, camera or microphone to a fileAVSCRUBStrip the metadata from a video or an audio fileHUSHBleep, silence or garble the words in a recording
Passwords, keys and codes9
KEYSA password vault that lives in this browserPHRASEPassphrases, passwords and recovery phrasesSHADOWKEYCheck password strength and make strong ones, offlinePWNCHECKCheck if a password has been breachedTOKENTwo-step login codes without an app or an accountMIGRATORMove and audit a password vault privatelyPAPERKEYPrint a key you can actually type back inSHARDSplit a secret into piecesKEYPRINTCheck an SSH key's fingerprint, type and size, and audit authorized_keys
Encrypting and sending7
CAPSULEAn encrypted file anyone can open in a browserCIPHEREncrypt a message to paste anywhereKEYRINGMake an age key pair and encrypt files to oneVAULTSend a file browser to browserLOCKBOXHand over work once you are paidAIRGAPMove data across a cameraSTRONGBOXMake, or open, a password-protected zip on this device
Hiding things inside other things6
PHANTOMStore a key or secret inside an image filePALIMPSESTHide a message in an image, or reveal oneGLYPHHide a note inside ordinary text, or reveal oneUNSEENFind the characters in a text that you cannot seeSTEGOSCANLook for data hidden inside an imageCADENCECheck the writing habits that identify you
Secrets in code and configs4
Looking inside any file9
Sovereign ConsoleAnalyse a file end to end in one air-gapped workbenchX-RAYRead what a file is hidingOPTICRead the text in a photo or a scanSENTINELFind keys, passwords and card numbers before you shareCLEANROOMOne pass to strip everything before you send a fileMANIFESTSee what an app or a browser extension asks for before you install itSIEVESort files into known and unknownMAGICIdentify a file's real type from its bytes, and catch a wrong extensionCARVERecover files hidden inside a memory dump or disk-image fragment
Files and formats6
Certificates, tokens and proofs9
CHECKSUMVerify a download was not tampered withPROVENANCEProve a file has not changed since you got itCERTLENSTake a certificate or a chain apart and check itSIGNETCheck a signed email or .p7m file, see who signed it, and take the signed file outVOUCHCheck who signed a Windows .exe or .dll, and whether it has changed sinceSTAMPCheck an RFC 3161 timestamp (.tsr) against the file it is for, in the browserJOTRead and check a JWT without sending it anywhereSIGILCheck the signature on a download without installing anythingASSERTRead a SAML response and check it without sending it anywhere
Keeping this device to yourself10
MIRAGEA decoy workspace if a device is takenDEADBOLTClear your traces on a shared computerEXPUNGEGet yourself off the people-search sitesFINGERPRINTSee what your browser tells every site you visitJOURNALA private journal, encrypted at restTRAILCut your home out of a run or ride before you share the trackTAKEOUTOpen the data Google, Meta or Apple gave you and see what they were keepingVITALSRead an Apple Health export.zip: every record type, day by day, as CSVPOSTBAGOpen an .mbox file or a Gmail Takeout zip and read every email in itCABINETOpen an Outlook .pst or .ost and save its email as .eml or .mbox
Covert work3
Test and demo data2
Record Suite 67 tools
Turn evidence and paperwork into records that hold up. Free to check a file with, like every tool outside the Workspace.
Proof and evidence8
PROOFProve a set of files has not changedATTESTCertify electronic evidence with a hash of every fileARCHIVEFreeze a web page as evidence with a hashCHAINKeep a chain of custody logPDFSIGCheck what a signed PDF really says about itselfSTATEMENTWrite a statement and seal it with a digestINVENTORYRecord the condition of a home, room by room, with photos that can be provedSNAPTake a photo that carries its own proof: hash, time and place
Disclosure and bundles9
DOCKETBuild a disclosure schedule from a folderEXHIBITBind exhibits into one PDF with Bates numbersBUNDLEBuild a paginated bundle with a linked indexPRIVLOGBuild a privilege log and check itREDACTLOGRecord what was redacted and why, in a scheduleDOSSIERTurn a chat export into a numbered transcriptSCREENSTurn a stack of chat screenshots into a transcript, each one an exhibitPOSTTurn a mailbox export into a numbered correspondence bundleFOLIOPaginate a transcript so it can be cited
Deadlines and the clock6
DIARYWork out deadlines and show the countingDSARTrack a subject access request and its deadlineBREACHRun the clock on a data breach and write it upABSTRACTFind the dates a contract hopes you missREQUESTDraft a freedom of information or subject access request, and run its clockCUSTODYRun the PACE detention clock
Registers and logs11
HOLDIssue a litigation hold and keep the registerSERVEWrite a proof of service and keep the registerCONSENTKeep the record that proves consent was givenCONFLICTKeep a register of interests that actually gets usedTHREADKeep a contemporaneous note of every conversationRETENTIONSay what you keep, why, and for how longROPAKeep the record of processing activities that Article 30 asks forDECISIONKeep a decision log that shows tamperingMATCHScreen names against a watchlistSANCTIONTrack covert authorisations and their review and expiry datesLOGBOOKKeep a sealed observation log that shows any change
Writing it up7
WITNESSWrite a witness statement that holds upMINUTESWrite minutes with the decisions picked outTAKEDOWNDraft a DMCA, GDPR or removal noticeACCESSWrite a subject access request under the GDPR, UK GDPR or CCPAINTERVIEWPlan, run and write up an interviewCLAUSEA clause library, and a document assembled from itDEMANDWrite a letter before claim for a deposit, a refund or money owed
Building a case7
At the scene5
Before you release it2
Money12
INVOICESBill people without telling a serviceLEDGERA cash book that adds up, with the summary an accountant wantsCOSTSBuild a schedule of costs that adds upMILEAGEKeep a mileage log the tax office will acceptQUOTESend a quote or estimate, and turn it into the invoice when it is acceptedRECEIPTSPhotograph receipts and get a tidy expense list, read on your deviceDIGITSFind numbers that were made upSTRUCTURINGFind deposits split to stay under a thresholdRECONCILETwo lists that should agree, and the reasons they do notCASHFLOWWhen the money runs out, and what breaks itASSETSDepreciation that lands on the residualRECURWhat a subscription business is really doing
Standard Suite 28 tools
Tools that answer to a published limit, and say how much room is left. Free to check a file with, like every tool outside the Workspace.
Lifting and loading5
Height and escape3
Exposure and the body4
Hours and the road2
Electricity and heating6
VOLTDROPDerating and volt drop, and which bindsZSWhether a circuit will actually disconnectLUXHow many fittings, and where they goOHMWork out volts, amps, ohms and watts from any two, and an LED's resistorBANDSRead a resistor's colour bands, or find the bands for a valueBTUWork out the BTU or watts to heat a room or cool it with a room unit
How much to order5
CONCRETEMore than the volume of the holePAINTAnd which tins to buyAREAWork out the area of a room of any shape, in square metres and square feetTILEWork out how many tiles and boxes a floor or wall needs, and the groutGRAVELWork out how much gravel, sand, topsoil or mulch to order, by volume and weight
Cutting and setting out3
Trace Suite 24 tools
What a device, a network or a file left behind, and what can honestly be said about it. Every one runs on this device and sends nothing, because evidence is not something an analyst can paste into a website.
Networks and logs9
BEACONFind what is calling home on a timerLOGONFind which account went somewhere newHOMOGLYPHSee what a domain actually isDGAFind generated domain names in a DNS logWIRERead a packet capture without uploading itPLUGGEDSee which USB drives were plugged into a Windows PCSWEEPRead an Nmap scan, and see what changed since the last oneSENTRYRead a server log and flag brute force, scanning and attacksPIVOTMap an attack surface and find the privilege-escalation paths
Windows artefacts5
SHORTCUTRead the target, dates and origin machine from a Windows .lnkRECYCLEList what a Windows Recycle Bin deleted, from where and whenSPECIMENTake a suspicious Windows program apart without running itMFTRead an NTFS $MFT and catch files whose dates were rewrittenPREFETCHRead a Windows .pf: what ran, when and what it loaded
Detection engineering4
Files, pictures and figures4
Scenes, and where a thing came from2
Guides, help and the rest of the site
Start here28
HelpWhere to startWorkbenchGuidesAppsOther SuitesEngineering SuiteFoundryOBSCURA Photo Editor: Layers and Raw in Your BrowserPDF StudioCaseUmbraBooksOBSCURA Keep: Passwords and Documents, With No CloudOBSCURA Keep: Open a Package Left for YouOBSCURA Keep: What It Protects Against, and What It Does NotRootsResearchPracticeWriteAuthorshipCheck an Authorship recordSoundVectorEraseConverterAll toolsSettings
Guides63
Opening a file without the software that made itWas this file changed?Does a photo show where it was taken?What is hidden in a Word documentData still in a spreadsheet you deletedCan text under a PDF redaction be recovered?How to check a file has not been changedIs an email really from who it says?What the tracking on a link doesWhat a website learns before you clickIs it safe to upload a file to a free tool?A password you can actually rememberSend a file without it sitting on a serverWhat a QR code can hideRedacting for discoveryIs it safe to paste this into an AI?How to open a HEIC fileA Photoshop alternative in the browserDoes your printer hide tracking dots on every page?Can your writing style identify you?A free Docs, Sheets and Slides alternative with no accountA free notes app that keeps your notes as filesA free PDF editor that never uploads your fileMerge, split and reorder PDFs without uploading themMake a photo smaller without uploading itOpen an Excel file without Excel, without uploading itOpen a Word document without Word, without uploading itCompress a PDF without uploading itPassword protect a PDF, and what protects nothingPassword protect a zip, and what it still gives awayGet the text out of a picture without uploading itA password manager with no account and no cloudBlur faces and plates out of a photoSign a PDF, and which signature you needPDF to Word, and what gets rebuiltConvert coordinates, and the 700 m misreadingThe triage sieve and START, and where they disagreeWhy Windows will not open your AES-encrypted zipWhy your CSV opens in one columnWhy your .docx opens as XMLWhat a screenshot gives awayIs it safe to send a medical letter or test result?Is it safe to upload your payslip?What a PDF keeps after you delete a pageWas this PDF changed after it was signed?What a video file gives away about youDoes a PNG have GPS or EXIF in it?How to tell if a photo has been editedWhy a Word document's page numbers change on another computerA free Adobe Acrobat alternative for filling, signing and redactingHow to tell if an email has a tracking pixelAn AutoCAD LT alternative for 2D drawings in the browserUnprotect an Excel sheet when you have lost the passwordA Relativity, Everlaw or Logikcull alternative for small firmsHow to prove you did not use AI to write somethingA record of your writing process that you keepA Scrivener alternative that runs in your browserAn SPSS alternative that opens .sav files in your browserA QuickBooks alternative that keeps the books on your computerA Clio alternative that keeps a firm's files on its own computerFamily tree software without Ancestry: keeping the tree yourselfAn Adobe Illustrator alternative that runs in your browserAn Audacity alternative that keeps the recording on your computer