Compare PDFs
See exactly what changed between two versions of a PDF.
Choose PDF filess
or drop them anywhere on this page
PDF
Processed on your device — never uploaded
How to compare pdfs
- Drop in two PDF files — the original and the revised version.
- Choose diff granularity: word-level shows meaningful changes, character-level catches every typo fix.
- Review the highlighted diff, then download as HTML or plain text.
About this tool
Comparing two versions of a PDF contract, a report, or a specification is a common task with no obvious built-in solution. Word processors have track changes; PDFs do not. The workaround is extracting the text from both documents and diffing it, which is exactly what this tool does.
Word-level diff is the most useful default: it surfaces substantive changes — words added, clauses removed — without flagging every punctuation and whitespace adjustment as significant. Character-level is the right choice when you need to see every single change, including a hyphen becoming a dash.
Questions
Can it compare layout and visual differences, not just text?
No — this is a text diff, extracted from the PDF content streams. It detects when words were added, removed or changed. It does not detect that a paragraph moved position on the page, that a font size changed, or that an image was replaced. For visual comparison you would need to render each page and diff the bitmaps, which is a different and much heavier operation.
What if one of the PDFs is a scan with no text layer?
Comparison requires extractable text. A scanned PDF with no text layer will appear empty in the diff. Run the OCR tool on both files first to add a text layer, then compare.
How many pages can it handle?
Text extraction from large documents runs in a background worker, so the comparison can handle lengthy documents without freezing the page. Very long PDFs — hundreds of pages — may take 15–30 seconds to extract.