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. Needs an Apple Intelligence device — everything else works without it. Read comfortably System, Day, Night, and Sepia themes dress the desk around the page, which stays light like paper. Read single pages, a continuous scroll, or fit to width. On iPhone, a reflow view rewrites the page as plain wrapped text, reading photographed pages with on-device text recognition first. Add, rename, and delete bookmarks; they save with the document. 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 document. What can't be applied cleanly is refused and reverted, never saved damaged. 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. Turn part of a page into a tappable page or web link, and change where it goes later. 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 and tells you which pages it couldn't read. Merge, split, reorder, rotate, crop, and delete pages by dragging thumbnails; links and bookmarks to a deleted page go with it. Resize to a standard paper size, stamp Bates numbers, and compress 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. Existing signatures verify honestly, saying plainly when an issuer is self-signed or the document changed. Password-protect with AES-128 and control printing and copying. Fill AcroForm fields, flatten them, or export data as XFDF. Find anything Search titles and full contents at once, narrowed by collection, with results that open on the page. The index is built on your device and works across languages. One real app on three platforms The same native app on iPhone, iPad, and Mac, with full editing everywhere: a menu bar and shortcuts on the Mac, several windows at once on iPad and Mac, Shortcuts, Siri, and Spotlight throughout, and full-screen Present with no conversion. Private by construction No account, no analytics, no telemetry — everything happens on your device. The only outbound request is the optional signing timestamp, which carries a hash, never your document. Share through iCloud Drive only when you choose. No subscription. Buy it once.