Compare PDF Files Online
Choose two PDF files and see which text was added, removed or left unchanged, page by page.
First PDF (A, the older version)
Click or drop the first PDF here
Second PDF (B, the newer version)
Click or drop the second PDF here
How to Compare Two PDF Files
Comparing two versions of a contract, report or manual by eye is slow and easy to get wrong. This tool reads the text of both files, lines it up and marks what changed.
- Choose the first PDF (A): Pick the older or original version of the document.
- Choose the second PDF (B): Pick the newer or edited version. You can also drop both files on the first box at once.
- Set your options: Compare by lines or by words, and decide whether spacing and letter case should be ignored.
- Click Compare PDFs: Read the result. Green rows were added in B, red rows were removed from A, and the numbers on the left show the page in each file.
Key Features
- Page-aware results: Every changed row shows the page it came from in each PDF, plus a list of pages that contain differences.
- Line or word comparison: Choose whole lines for structured text or single words for flowing paragraphs.
- Ignore noise: Optionally ignore spacing and upper / lower case so only real wording changes remain.
- Focus on changes: Unchanged text is collapsed, with a little context kept around every change.
- Private by design: Both files stay on your device and are never uploaded.
Frequently Asked Questions
Does it compare layout, images or fonts?
No. It compares text only. A change in a picture, a colour, a font or the position of a block will not be reported unless the words themselves changed.
Can I compare scanned PDFs?
Not directly. A scanned PDF is a set of pictures with no text to read, so there is nothing to compare. If a PDF has been through OCR it contains text and can be compared, but OCR mistakes will show up as differences.
Why are there differences when both files look the same?
PDFs store text in pieces, and two exports of the same document can split or order those pieces differently. Try Words mode, which ignores line breaks, and keep "Ignore spacing differences" turned on.
What is the difference between Lines and Words?
Lines mode marks whole lines as added or removed, which is easiest to read for lists, forms and tables. Words mode compares single words, so a re-wrapped paragraph does not look completely changed.
Can I compare password-protected PDFs?
No. The tool cannot open protected files. Remove the password first, then compare the unlocked copies.
Are my PDF files uploaded anywhere?
No. Both files are read inside your browser and are never sent to a server. Only the PDF reader code is downloaded from a public library host when the page opens.