Compare two PDF files
Find what changed between two versions of a PDF: added and removed words, shown page by page.
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Choose the original and the changed version. The text of both is compared word by word and every change is shown on the page of the new version where it happens.
How it works
A new version of a contract, policy or price list arrives, and you need to know exactly what changed. Choose the original and the changed PDF: the text of both is extracted and compared word by word with the Myers diff algorithm, the same approach used by version-control tools. Added words are underlined in green and removed words struck through in red, grouped by the page of the new version where the change sits.
Unchanged pages are hidden so you can go straight to the edits, and the full comparison can be downloaded as a text report. Differences in line breaks and spacing are ignored; capital letters can be ignored too.
This compares text only: changes in images, layout, fonts or colours are not detected. Scanned PDFs have no text to compare, so run OCR PDF on both first.
What a comparison catches
| Change between versions | Reported? |
|---|---|
| A number, date or amount changed | Yes, as a removed and an added word |
| A sentence or clause added or deleted | Yes |
| Text that only reflowed onto the next page | No, the comparison runs across pages |
| Different line breaks or spacing | No, ignored on purpose |
| Capital letters changed | Yes, unless you tick "ignore case" |
| An image, logo, colour or font changed | No, only text is compared |
| A scanned page changed | Only after OCR PDF on both versions |
For contracts, compare the version you agreed with the version you are asked to sign, and read every highlighted change in context before signing; the report is a checklist, not a legal review.
How to use it
- Choose the original PDF.
- Choose the changed PDF.
- Click Compare.
- Review the highlighted changes page by page and download the report.
Frequently asked questions
Are my files uploaded?
No. The file is read and processed by your browser on your device; nothing is sent to a server. The PDF engine is downloaded from this site the first time you use a tool and then runs on your device.
Does it compare images or formatting?
No, only the words. A moved picture or a changed font is not reported; a changed number or sentence is.
What if text moved to another page?
The comparison is continuous across pages, so text that merely flows onto the next page is not reported as a change.
Why are some changes shown as one large block?
When two documents are very different, the comparison falls back to showing a large replacement to keep your browser responsive. It says so when that happens.
Can I compare scanned documents?
Run OCR PDF on both first; OCR errors may then show up as small differences.
Related tools
- Text DiffCompare two texts line by line or word by word and see additions and deletions side by side or inline.
- PDF to TextExtract the text of a PDF in reading order and download it as a .txt file or copy it.
- OCR PDFMake scanned PDFs searchable: Tesseract reads English and Arabic text and adds an invisible text layer.
- PDF to WordTurn a text-based PDF into an editable Word document with paragraphs and headings rebuilt.
- Merge PDFCombine several PDFs into one file in the order you choose. Runs in your browser; nothing is uploaded.