A revised PDF may change a number, a paragraph or only the layout. Compare PDFs creates a downloadable report with before-and-after previews, magenta visual differences and text excerpts where selectable text changed.
1. Put comparable pages in the same position
Choose the earlier file first and the revision second. Page 1 is compared with page 1, page 2 with page 2, and so on. The tool accepts two PDFs, up to 32 MB and 100 pages each.
If a new cover shifts the revised document by one page, keep the originals and make aligned copies with Extract PDF pages or Organize PDF. Review the added cover separately. The tool does not automatically match moved pages.
2. Try a revision with known changes
Download these synthetic proposals, then choose them in that order in the comparison tool:
- Earlier proposal (PDF, 2 kB): project fee $2,400.
- Revised proposal (PDF, 2 kB): project fee $3,200.
Choose Compare PDFs, then Download result. The example report (PDF, 179 kB) marks the changed digits on page 1 and lists the old and new fee in its text excerpts. Its 0.04% pixel difference describes a small visual area, even though the price changed substantially.
For a quick three-page exercise without downloading inputs, choose Load sample in the tool: the Cartons quantity changes from 6 to 7 on all three pages.
3. Read the report without overstating it
- Before / After: reduced previews of the page at that position. They help you locate a change; they are not full-resolution evidence.
- Visual differences: magenta pixels exceed the comparison tolerance. A pixel percentage is not a percentage of words or meaning changed.
- Text differences: minus lines are from the earlier file; plus lines are from the revision. Excerpts are limited, so a long rewrite may not appear in full.
- Added / Removed page: only one file has a page at that position. An insertion in the middle can shift the remaining comparisons.
4. Check scans and fine print in the originals
Scanned pages can be compared visually, but image-only words do not produce text excerpts. A shifted scan, different export settings or a font change can create marks without changing the wording. Conversely, tiny details may disappear in a reduced preview.
No detected difference means no difference was found by these checks. It does not establish byte-for-byte identity, equivalent legal meaning or valid signatures. Hidden metadata is not compared.
Hosted comparisons process the uploads on our server and remove the uploaded files after each operation. Save the report before leaving the tool. Read file privacy or compare your two versions.