Compare PDF
Spot every text change between two versions of a PDF, line by line. Added and removed lines are highlighted. Runs 100% in your browser — no uploads.
Compare Two PDFs and See Exactly What Changed
Drop in the original and the revised PDF and get a line-by-line diff in seconds. Added lines are highlighted green, removed lines red, and identical stretches are folded away so only the real changes are in front of you — with a count of how many unchanged lines were skipped. Ideal for checking a contract redraft, a policy update, a resubmitted report or a supplier quote where nobody told you what moved. Copy the report or download it as a plain text file for your records. 100% browser-based, completely private, free, and no watermarks.
Why Use Our PDF Comparison Tool?
- Real diff, not a summary: A longest-common-subsequence comparison shows the exact lines that were added and removed.
- Changes-only view: Unchanged passages collapse into a single "N unchanged lines" marker, with a toggle to show everything.
- Shareable report: Copy the diff to your clipboard or download it as a .txt file with page counts and totals.
- 100% Private & Free: Both documents stay on your device — nothing is uploaded, and there are no limits or sign-ups.
How to Compare Two PDF Files
- Select the original PDF on the left and the revised PDF on the right.
- Click "Compare PDFs" — both text layers are read locally.
- Read the highlighted diff, or tick "Show unchanged lines" for full context.
- Copy or download the report if you need to pass the changes on.
Comparing plain text or code instead? Try our text diff checker. Need the full contents of one file? Use PDF to Text.
Frequently Asked Questions
How do I compare two PDF files?
Choose the original and the revised PDF, then press "Compare PDFs". The text of both is read in your browser and the differences are highlighted line by line.
Does it compare images and layout?
No. Only the text layer is compared. Formatting changes, images, fonts and colours are not part of the diff.
Does it work on scanned PDFs?
No. Scanned pages contain no selectable text, so there is nothing to compare until the file has been through OCR.
Is there a size limit?
Large documents are handled by trimming the identical start and end, then comparing up to 2,000 differing lines. If more differ, the tool tells you how many were left out so the comparison stays fast.
Can I save the comparison?
Yes. Copy the report to your clipboard or download it as a plain text file that lists every added and removed line.
Are my PDFs uploaded anywhere?
No. Both files are read entirely in your browser and never leave your device.