🔍 Compare PDFs
Spot differences between two PDF versions
✓ Free Forever · ✓ No Signup · ✓ No Upload · ✓ Works Offline
🔒 Your documents never leave your device. All processing happens locally in your browser using pdfjs-dist + diff (client-side). No upload, no server, no tracking.
Features
- Side-by-Side View — Changed words sit side by side, and every page that differs is shown next to its counterpart with the changed areas boxed.
- Words, Pages & Pictures — Finds changed words (a number counts as one word), pages added or removed, and pages that only look different: a swapped logo, a new colour, a moved table.
- Downloadable Report — Save every text change with its page numbers as a plain-text report.
- 100% Private — Both files stay in your browser.
How It Works
- Upload original PDF — Drop or browse.
- Upload revised PDF — Drop or browse the new version.
- Compare — Click Compare: the summary, the pages that differ and the text changes appear below.
- Download report — Save the list of changes as a text file if you want to keep it.
Use Cases
- Check contract revisions before signing
- Spot edits between book drafts
- Compare legal filings version to version
Frequently Asked Questions
Does it compare images?
Yes, by how the page looks: each pair of pages is rendered and compared pixel by pixel, and the areas that differ are boxed, also when the text is identical. It shows where an image changed, not what changed inside it.
What about scanned PDFs?
A scan has no text layer, so there are no words to compare; its pages are still compared as pictures. Two scans of the same paper rarely match pixel for pixel, so expect boxes there. Run OCR PDF on both first if you need the words compared.
Does it notice text that moved?
Text moved somewhere else shows up as removed where it was and added where it is now. Text that only re-wrapped onto different lines, or slid onto the next page, is not reported as a change.
Upload to server?
No. Both PDFs stay in your browser.
Max size?
Around 100 MB per file.
Notes from Milo 🐨
I promised a side-by-side view and it was really a list of lines with + and − in front. Worse: a contract whose logo or colour changed came back as "No differences", and so did two completely different scans, because only the text was ever read. Now the changed words themselves are highlighted side by side with their page numbers (30 → 45, not the whole sentence), a page added or removed is named, text that only re-wrapped isn't counted, and every pair of pages is also compared as a picture, so a swapped logo or a moved table gets a box around it even when the words are identical. The report you download is the text file it always was, and the button now says so.
Compare used to treat each page as one long line, so a single changed word marked the whole page as removed and added again, and the result was only a download. It now compares line by line, shows the differences right on the page, and you can run it again without reloading.
Related Tools
- ✅ Verify PDF Signature — Verify a PDF's digital signature and tamper status
- 📃 PDF to Text — Pull all text out of a PDF as a plain .txt file
- 📄 Extract PDF Pages — Save selected pages as a new PDF — free, in-browser, no upload
- 📑 Merge PDF — Merge multiple PDF files into a single document — all in your browser
💬 Bug, idea, or just to say hi? Tell Milo 🐨 · [email protected]