PDF Colophon: Edit & Sign

PDF Colophon is a document studio for iPhone, iPad, and Mac that can answer questions about your own documents. Read, edit, annotate, organize, redact, and sign — without exporting between apps, and without your files leaving your device. Ask your own library Ask what a contract commits you to, or what recurs across a hundred documents you haven't read in a year. Colophon retrieves the relevant passages and answers with citations to the exact pages, so you can check the source rather than trust the summary. Scope a question to one document, a collection, or everything you own. It runs on device through Apple Intelligence; conversations save as plain Markdown you can open in Files. This feature needs a device that supports Apple Intelligence. Everything else below works without it. Edit the real page Tap any text block or image and change it in place. Colophon rewrites the document's actual text and image objects, so the page stays vector and searchable instead of being flattened into a picture. Change wording, swap an image, add a text box, or run Find & Replace across the whole document, with Apple Writing Tools to rewrite or proofread. When an edit can't be applied cleanly, the app refuses and reverts rather than handing back a damaged file. Redaction that actually removes Mark what's private and apply. The text and vector art underneath are deleted from the content stream and image pixels burned opaque, then a verification pass confirms nothing extractable is left. If removal can't be proven, the redaction is refused and rolled back — rather than covering your secrets with a black rectangle that lifts off in any other reader. Mark up anything Highlight, underline, strike through, draw freehand with pressure-responsive ink, and add comments, arrows, lines, boxes, ellipses, and callouts. Annotations sit on top of the page and lift off cleanly. Export a summary of every mark as Markdown when you need to send notes instead of the file. Scan, recognize, organize Capture pages with the camera, with edge detection and perspective correction, or Continuity Camera on the Mac. On-device text recognition adds an invisible searchable layer to scans, so an old paper document becomes findable and readable by VoiceOver. Merge, split, reorder, rotate, crop, and delete pages by dragging thumbnails, or combine documents into one. Resize to a standard paper size, stamp Bates numbers, and compress by recompressing images, leaving text and fields alone. Sign and protect Draw a signature, or sign cryptographically. Colophon embeds a real PKCS#7/PAdES digital signature — with an identity it generates or your own .p12 — and adds an RFC 3161 trusted timestamp so the signature outlives its certificate. Existing signatures verify honestly, saying plainly when an issuer is self-signed or the document changed after signing. Password-protect with AES-128, and control whether a reader may print or copy. Fill AcroForm fields, flatten them into the page, or export data as XFDF. Find anything Search titles and full contents at once, narrowed to a collection when you want. Results show the page and a highlighted snippet and open the document there. The index is built on your device and works across languages. One real app on three platforms iPhone, iPad, and Mac run the same native app, with full editing everywhere and no cut-down companion. The Mac gets a real menu bar and the shortcuts you expect. Shortcuts, Siri, and Spotlight reach your library through App Intents. Present any document full screen, with no conversion to slides. Private by construction No account, no analytics, no telemetry. Your documents are processed on your device. The only request Colophon makes to a server is the optional timestamp when you digitally sign, which carries a cryptographic hash and never your document. Share through iCloud Drive only when you choose — that single file, in your own account. No subscription. Buy it once.