To compare two PDF files, open the first one in OpenPdfEdit, choose Compare, and pick the second. A panel lists each line of text that differs, page by page, with the old wording crossed out and the new wording beside it. Click an entry and the app takes you to that place in the document.
It runs in your browser tab. Neither file is uploaded, and you do not need an account.
Step by step
- Open openpdfedit.com/app and choose Open PDF…. Pick the older of the two versions.
- In the toolbar, choose Compare. It is in the Document group while the app is in Read. In Annotate or Edit, look under All tools.
- A file dialog opens. Pick the newer version.
- The Compare panel opens on the right. Its first line names the file you compared with. The number beside the title is how many differences were found, and they are listed under a heading for each page.
If nothing differs, the panel says "No differences found."
You can also start from the first screen, before any file is open. Choose Compare in the list of tools, pick the first file, then the second.
How to read the list
Each entry is one of four kinds.
A changed line. The line from the open document is shown in red and struck through. After the arrow comes the same line from the other file, in green and underlined:
The Client will pay the Supplier a fixed fee of USD 12,000 for the services, plus any expenses → The Client will pay the Supplier a fixed fee of USD 15,000 for the services, plus any expenses
The whole line is shown, and the changed word is not marked on its own, so read the two versions against each other. Small edits are listed as well: one digit, a missing comma, a capital letter.
Red only. The text is in the open document and not in the other file. If you opened the older version first, this text was removed.
Green only. The text is in the other file and not in the open one. It was added.
"Drawn differently; the text is the same". The words on that page match, but the page does not look the same. You get this when a picture was replaced or moved, or when a signature or a highlight was added.
Click an entry to go to it. For a changed line or for red text, the app outlines the lines on the page. For a page that is drawn differently, it shades the area that differs.
Green-only text is not in the open document, so there is nothing to outline. The app shades the place where that text sits in the other file, and in the open document other text may be there. To see added text where it belongs, run the comparison the other way round: open the newer version and compare it with the older one. The same passage is then listed in red and outlined on the page.
If the files do not have the same number of pages, the panel says so at the top, for example "This document has 3 pages; the other has 4." A page that exists only in the second file is marked "Only in the other document".
Keeping a record of the changes
The list exists only on screen. The panel has no export, and closing it discards the list. To see it again, choose Compare and pick the file again.
Comparing does not change either file.
If you need something to send or to file, mark the changes on the document yourself:
- With the Compare panel open, switch to Annotate. The panel stays where it is.
- Click an entry to jump to it, choose Highlight in the tool list on the left, and drag across the line.
- Repeat for the other entries, then choose Save a copy. The copy is offered under the same file name as the original, so change the name to keep both.
There is more about the markup tools in annotating a PDF.
What the comparison cannot tell you
It compares page 1 with page 1, page 2 with page 2, and so on. When new text pushes a paragraph onto the next page, that paragraph is listed in red on one page and in green on the next, although its wording has not changed. When a whole page was inserted, every page after it is listed as changed. So if a red entry on one page is matched by the same text in green on the following page, the text has moved. It has not been rewritten.
It compares line by line. If the second file was laid out differently, with another font size or other margins, the lines break in different places. They are then listed as changed even where the words are identical. The result is cleanest when both files were made the same way.
Scanned pages have no text to compare. A scan is a picture of a page. Compare a scan with an ordinary PDF and the full text of every page is listed as a difference. Compare two scans and the list can only say which pages look different. Two scans of the same sheet do not match dot for dot, so expect every page to be listed.
Your files stay on your computer
OpenPdfEdit compares the files inside the browser tab. Both PDFs are read from your disk. Nothing is uploaded.
It also works without a connection. Open the app once while you are online and let it finish loading. After that you can reload the page with the network off and compare as usual.
FAQ
How do I compare PDF files for free?
Open the first file in OpenPdfEdit, choose Compare, and pick the second. Comparing is free, and there is no account to create.
Are my PDFs uploaded when I compare them?
No. Both files are read and compared inside the browser tab.
Does it show the two PDFs side by side?
No. One document is open, and the differences are listed in a panel beside it. Clicking a difference takes you to it on the page.
Can I save or export the comparison?
Not as a report. Highlight the changed lines in Annotate and save a copy, as described above.
Can I compare scanned PDFs?
Not by their text, because a scan has none. The list can only show which pages look different.
Does comparing change my files?
No. Both files are left as they were.
Can I compare PDFs offline?
Yes. Open OpenPdfEdit once while you are online. After that it works with the network switched off.