Compare PDF
See every line added, removed or reworded between two versions of a PDF.
What Changed Between Version 3 And Version 4?
When a contract, a policy or a report comes back “with a few small changes”, the only safe assumption is that you need to see all of them. Reading two long PDFs side by side misses things; this tool extracts the text from both and lines them up, so every added, removed or reworded line is marked with the page it is on.
Both files stay on your device, which matters for exactly the kind of document people compare. Spacing differences can be ignored so that a re-flowed paragraph does not show as a change, and the full comparison can be saved as a text report.
Key features
- Line-by-line differences — additions and removals highlighted, with page numbers.
- Ignore spacing or case — so re-typeset text does not drown out real edits.
- Changes-only view — unchanged passages collapse, with context kept around each edit.
- Summary counts — lines added, removed and pages affected at a glance.
- Downloadable report — a plain text record of every difference.
This tool runs entirely inside your browser using native Web APIs. Your files and text are never uploaded to a server, never logged and never shared with third parties.
How to use: Compare PDF
- Drop in the original
The earlier version goes on the left. - Drop in the changed version
The comparison runs as soon as both are loaded. - Read the differences
Red lines were removed, green lines were added; page numbers show where. - Save the report
Download a text record of the comparison if you need to keep one.
Technical specifications
| Processing location | Entirely in your browser — no server round trip |
|---|---|
| Data uploaded | None. Files and text never leave your device |
| Price | Free — no account, no trial, no usage cap |
| Category | |
| Works offline | Yes, once the page has loaded |
| Browser support | Chrome 90+, Edge 90+, Firefox 90+, Safari 15+ |
| Interface languages | English, 中文, हिन्दी, Español, العربية |
Frequently asked questions
Does it compare images and layout?
No — it compares the text. A moved image, a changed font or a new colour will not show up. For contracts and reports, the text is almost always what matters.
Why does a scanned PDF show no text?
A scanned page is a photograph of text, not text. Comparing scans needs OCR first; once a PDF has a real text layer, it can be compared here.
Why do some unchanged lines show as changed?
If one version was re-typeset, lines may wrap at different words, so the same sentence breaks differently. Ignore spacing helps; the change is still easy to read because both versions of the line are shown together.
Is there a size limit?
The comparison works well for documents of hundreds of pages. If two files differ in more than 2,500 lines, they are almost certainly not versions of the same document, and the tool says so rather than listing everything.
Are my documents uploaded?
No. Both PDFs are read and compared in your browser on your own device.