Compare PDF
Drop the original and the revised file. Changed words are boxed on the pages and listed with page numbers.
Free · runs in your browser · nothing is uploaded
Compare PDF is a free tool that checks two PDF files against each other and lists the differences it finds. You drop the original file in one box and the revised file in the other, and the tool reports words that were removed, added or changed, with page numbers for each one. It runs in your browser tab with no account or sign-up, so you can start comparing right away. It can also show differences in layout and images, which makes it useful for checking a final version against an earlier draft.
Export the list as a CSV file or an HTML report when you are done.
How to use the PDF compare tool
- Drop the older or original PDF into the Original drop zone.
- Drop the newer PDF into the Revised drop zone. If you placed them the wrong way round, click Swap the two files.
- Turn on Ignore upper and lower case or Ignore punctuation if you do not want those changes to count.
- Keep the default Side by side view to read the text, or pick Picture overlay or Changes only.
- In Picture overlay, leave Forgive shifts of one pixel on, which is the default, to skip tiny offsets. Turn it off for a stricter check.
- Work through the results using the page arrows, which pair pages by number.
When you are done, you can export the changes as a CSV file or save an HTML report. Both keep a record of each difference, so you can share the result or check it later.
Click a line in the list to open its page. The page pair appears side by side with the changed words boxed, so you can judge each change in context. Use Download changes (CSV) for a spreadsheet, or Download report (HTML) for a page you can print or save as PDF from your browser.
How can I compare two PDF files?
Load the original PDF in the Original box and the newer version in the Revised box, then open the Changes only view. It lists every removed, added and changed item with a link to its page. Click an item to jump to that page and see the change in context.
- Open Changes only to get the full list. Each entry is marked removed, added or changed.
- Click an entry to jump to its page, then switch to Side by side to see removed words boxed red on the original and added words boxed green on the revised.
- Check the page counts. If they differ, the tool reports it, so look for pages that were added or dropped at the start or end.
- If the words match but the page looks different, switch to Picture overlay and review the coloured areas.
- Export the changes CSV, which has the columns change, page_a, text_a, page_b and text_b, or the HTML report, to keep a record.
How does a PDF compare find differences?
The tool reads the words on every page of both files, lines them up, and flags anything that was removed, added or changed. Files without a text layer, such as most scans, have no words to read, so the picture overlay is the only way to compare them. Fonts, images and layout changes that leave the words unchanged appear only in the overlay.
| View | What it shows | Use it when |
|---|---|---|
| Side by side (default) | Both pages, with removed words boxed red on the original and added words boxed green on the revised | You want to read text changes in context |
| Picture overlay | Dark pixels only in the original in red, only in the revised in green, and in both in grey, plus the share of dark pixels that differ | Fonts, images or layout changed, or the file is a scan |
| Changes only | A list of removed, added and changed items with page links | You want a checklist of every change |
Frequently asked questions
Can I compare two PDF documents for differences?
Yes. Each difference is labelled removed, added or changed and includes its page number and the text involved.
Does it detect formatting changes?
Text is compared word by word, so a change in font, size or colour does not register as a text change. Those changes appear in the Picture overlay view, which shows dark pixels that differ between the two files.
Can it open password-protected PDFs?
Yes. A box asks for the password when you load a locked file, and the password stays in your tab.
What happens to the documents I compare?
Nothing is uploaded. The comparison runs in your browser tab, and the tool keeps working with the network switched off after the first load. The PDF engine, about 2 MB, downloads the first time you open a file.
Is it free? Do I need an account?
The tool is free to use. You do not need an account, and there are no ads, analytics or cookies.
Can it compare scanned PDFs?
Not by text. The tool has no OCR, so a scan without a text layer has no words to compare. Use the Picture overlay view instead.
What happens if the page counts are different?
The tool reports the difference in page counts. Use the page arrows to check which pages were added or removed.
Does the tool decide which changes matter?
No. It shows what changed, and you decide what to remove or keep. The tool is not legal advice, so look at the result yourself before you rely on it.
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