PDF Compare
Find what changed between two versions of a document with our PDF Compare tool. It extracts the text of both PDFs page by page and reports every added and removed line, page by page, together with differences in page count, title, author, producer, dates and other metadata. Ideal for contracts, terms, reports and specifications, when you need to see exactly what an edited version adds or removes before you sign or publish.
Frequently asked questions
How do I compare two PDFs?
Upload two PDF files and click Compare PDFs. The first file is treated as the original and the second as the new version, so lines only in the second file show as added and lines only in the first as removed.
What exactly is compared?
The tool compares the text of each page line by line, the page count and the metadata: PDF version, title, author, subject, keywords, creator, producer, creation and modification dates and language. Layout, fonts, colors and images are not compared.
How are differences shown?
Each changed page gets its own section with a diff block in which removed lines start with a minus sign and added lines with a plus sign. A summary at the top counts the changed pages and the added and removed lines.
Why is a whole paragraph marked as changed when I edited one word?
The comparison works on lines as the PDF lays them out. A changed word changes its line, and when the text reflows, the following lines of the paragraph change as well. Look for the removed and added pair to spot the edit.
What happens when the PDFs have different page counts?
Pages are compared by position. Pages that exist only in one document are reported as entirely removed or entirely added, with a note saying which PDF they belong to.
Can I compare scanned PDFs?
Only if they contain a text layer from text recognition. A scan without one has no text to compare, so both documents would appear identical. Run text recognition on the scans first.
Is there a limit on the size of the report?
The report shows up to 500 changed lines and cuts lines longer than 300 characters, and it says when it does. The counts in the summary always cover every change, and a page with too many lines for a line by line diff is shown as fully replaced.
How large can the PDFs be?
Each PDF can be up to 10 MiB with at most 200 pages, and both together up to 20 MiB. Exactly two files are needed for each comparison.
Can I compare password protected PDFs?
Yes. Enter the password of the first PDF in the first password field and the password of the second in the second field. Leave a field empty when that PDF opens without one. Passwords are never shown in the result.
Are my documents stored?
No. Both files are read in memory for this request only and discarded once the report is returned. Nothing is kept on the server.