Compare PDF
See exactly what changed between two versions of a PDF, highlighted at a glance — right in your browser.
Drop your files hereTap to add your files
or click to choose · nothing leaves your device
Private by design. This tool runs entirely in your browser — your file is processed on your device and is never uploaded to us. How this works
Compare PDF takes two versions of a document and shows you precisely what changed — edited text, moved paragraphs, added or removed elements, a swapped image. Instead of squinting between two files, you get a single marked-up PDF with every visual difference highlighted in red, so a revised contract, proof or report reveals its changes instantly.
The comparison happens entirely in your browser. Both files stay on your device — nothing is uploaded — which matters when you’re reviewing sensitive drafts. It’s free, with no account and no watermark.
How it works
Ream renders each page of both PDFs and compares them pixel for pixel. Wherever the new version differs from the original, that area is tinted red on the output, so changes jump out while the unchanged text stays readable underneath. If a page exists in only one of the two files (a page was added or removed), the whole page is flagged. You download a single comparison.pdf, plus a summary of how many pages differ.
How to Compare PDF
Add both PDFs
Add the original first and the new version second — use the arrows to set the order. Both stay on your device.
Run Compare PDF
Ream lines up the pages and highlights every difference.
Download the marked-up PDF
Save comparison.pdf with the changes highlighted, and read the summary of what differs.
What it catches
Because it compares what’s actually on the page, it catches any visible change, not just text:
- Edited text — a changed figure, a reworded clause, a fixed typo.
- Moved or reflowed content — shifted paragraphs, new line breaks.
- Added or removed elements, stamps, signatures or images.
- Whole added or deleted pages, flagged in full.
Getting a clean comparison
- Put the files in the right order — original first, revised second — so the highlights sit on the new version.
- Comparison is page by page: page 1 to page 1, and so on. If a page was inserted early on, later pages will read as “changed” because everything shifted — that’s expected.
- Two scans of the same document may show minor speckle from scanning differences; two exported PDFs compare cleanest.
Private by design
Reviewing changes often means handling confidential drafts — contracts, agreements, unreleased documents. Compare PDF runs on your own device, so neither file is ever uploaded to a server. The whole review stays with you.
Why choose Ream
Every change highlighted
Differences are marked in red on a single PDF, so nothing gets missed.
Catches any visible change
Text edits, moved content, added or removed elements and whole pages.
Runs in your browser
Both files stay on your device — nothing is uploaded.
Free, no watermark
No account, no watermark, no limits.
Frequently asked questions
How do I compare two PDFs?
Add the original first and the new version second, then click Compare. You download a PDF with every difference highlighted in red.
What kinds of changes does it show?
Any visible change — edited text, moved paragraphs, added or removed elements or images, and whole added or deleted pages.
Does the order of the two files matter?
Yes — add the original first and the revised version second so the highlights land on the new version. Use the arrows to set the order.
Are my files uploaded?
No. The comparison runs entirely in your browser, so both PDFs stay on your device.
Why is every page after an inserted page marked as changed?
Comparison is page-by-page. Inserting a page early shifts everything after it, so those pages genuinely differ from the originals at the same position.
Is it free?
Yes — free, no sign-up, and no watermark.