How do I compare two PDFs for changes?
To compare two PDFs, drop the original into the first box and the changed version into the second on FixDoks's Compare PDF tool. It lines up the text word by word, showing removed words in red and added words in green with a change count. Turn on Only show changes to skip identical sections, all inside your browser.
Compare PDF at a glance
| Inputs | Two PDF files |
|---|---|
| Output | Word-level diff view |
| Processing | In your browser; your files are not uploaded |
| Price | Free, no watermark |
| Download | Free Google sign-in |
| Works on | Chrome, Edge, Safari and Firefox on Windows, Mac, Android and iPhone |
How to use Compare PDF
- Drop the original PDF into the first box and the changed version into the second.
- FixDoks compares the text word by word and shows a side-by-side view.
- Removed words are marked red on the left, added words green on the right.
- Turn on Only show changes to hide unchanged sections and scan just the differences.
What does the comparison cover?
FixDoks compares the text content of two PDFs word by word, not the images, layout or visual design of the pages. It lines up the two documents, finds where the wording differs, and shows the original on the left with removed words highlighted in red, and the changed version on the right with added words highlighted in green. A count of how many words were added and removed sits above the view so you can judge the scale of the changes at a glance, without reading every line.
Reading the result
Unchanged text appears plainly on both sides so you can follow the surrounding context of each change. A red word on the left with no matching green word on the right means it was deleted outright. A green word on the right with no matching red word means it was newly added. Where a phrase was reworded, you will typically see the old phrase in red and the new phrase in green sitting close together, which makes it easy to spot a rewritten sentence rather than just scattered edits.
Only show changes
For a long contract, report or manuscript where most of the text is identical between versions, scrolling through every unchanged paragraph to find the handful of edits is slow. Turning on Only show changes collapses the unchanged sections so you only scroll past the places where the text differs, which is the fastest way to review a redline on a long document.
What this tool does not compare
- Images, logos, charts and diagrams are not compared, only the text.
- Layout and formatting differences, like a font change or a moved paragraph without wording changes, are not flagged.
- Page numbers, headers and footers are compared as text like anything else, so a version stamp or date in a footer may show up as a change even if the body is identical.
Typical uses
| Situation | What comparison shows you |
|---|---|
| Two drafts of a contract | Every clause that was reworded, added or removed between versions. |
| A resubmitted form or application | Whether the applicant actually changed the answers you asked about. |
| An edited manuscript or report | A quick way to see an editor's changes without a manual re-read. |
Tips
Compare the same type of document both times, for example both text-based PDFs; a scanned page with no text layer will show as entirely different since there is no extractable text to line up. If the two files use very different layouts, such as one with two columns and one with one column, word order in the comparison may look unusual even when the actual wording matches, since text is read in the order it is stored, not necessarily the order it appears visually. For a full, page-by-page visual check rather than a text diff, open both PDFs side by side manually.