Compare Two PDF Files Online: Find Text Differences Without Uploading

Open this page, drop the older PDF into slot A and the newer PDF into slot B, then press Compare. The tool reads the text of both files in your browser and shows every added and removed line side by side with page numbers. It is free and needs no account.

A PDF diff checker, also called a PDF comparison tool, finds the differences between two versions of a PDF. This one extracts the text of both files and lists every line that was added or removed, with the page number of each change.

No. Both files are parsed with pdfjs-dist inside your browser, and the comparison runs locally. Your documents never leave your device. You can confirm this in your browser Network tab while comparing.

Yes. ToolDeck PDF Compare reads both PDFs locally in your browser, so no file is sent to a server. This is useful for contracts, financial documents and anything confidential.

It depends on what changed. For wording, number and clause changes, a free text diff like this one is fast and private. For layout, image or font changes, use a visual overlay comparison, such as the Compare Files feature in Adobe Acrobat Pro (a paid feature at the time of writing).

Put the older contract in slot A and the newer one in slot B. Review the summary counts, then read each added and removed line. Check every changed number, date and defined term against the original PDF before you sign.

It compares the extracted text layer of each PDF, line by line. Added and removed lines are highlighted, and every change carries the page number where it appears.

The tool extracts the text of each page with pdfjs-dist, then runs a Longest Common Subsequence diff over the lines. Lines that appear in both files stay paired. Lines found only in A are marked removed and lines found only in B are marked added.

No. This is a text comparison. Images, colours, fonts and layout are not checked. If two versions differ only in a logo or a font, the tool will report them as identical. Use a visual overlay viewer when appearance matters.

Only if the PDF already has a text layer, for example after OCR. A raw scan is a picture of words, so there is nothing to compare. Run the scan through OCR first, then compare the searchable copy.

The comparison is line-level, not word-level. When any word inside a line changes, the whole line is reported as removed from A and added to B. Read the two versions side by side to spot the exact edit.

Every line on the affected page appears as added or removed, and every page after it shifts by one. The highlights stay correct, but page N in file A may pair with page N+1 in file B from that point on.

We recommend files under 20 MB each for reliable browser performance. Very large documents may run out of device memory, especially on phones.

Yes. It works in Safari on iPhone and Chrome on Android. For best results on mobile, keep each PDF under 10 MB.

The tool compares exactly two files at a time: the older version and the newer version. To compare a third version, run another comparison against the one you already trust.

Once the page has loaded, both PDFs are read locally and the comparison runs without further network requests. Opening the page initially needs internet.

No. There is no server storage and no account. The comparison exists only in your browser tab until you close it or clear the files.

Yes. You can copy the summary and the changed lines as text. Downloading a formatted report PDF is on the roadmap.

No. Only the body text layer is compared. Comments, highlights, sticky notes and markup are not read.

Yes, because the files are processed locally. For extra caution, use a private browsing window so cached data is cleared when you close the tab.

The summary shows zero added and zero removed lines, and the view states the documents are identical in text. Any visual difference will not be detected.

Text extraction can differ when a PDF was re-saved by a different program, even if the visible text looks the same. Line breaks, ligatures, whitespace and hidden characters sometimes shift.

You can, but treat the output as a helper, not a certified audit. For legal work, review every flagged line against the original PDF and keep both versions on file.

Current Chrome, Edge, Firefox and Safari on desktop and mobile. Keep your browser updated for the best PDF parsing support.

Not directly. Convert the Word file to PDF first, then compare the two PDFs. Both files need a text layer for the comparison to work.

A visual comparison renders both pages as images and overlays them, so it catches layout and image changes. This tool reads the text, so it catches wording and number changes precisely but misses anything visual.

No. If a PDF is encrypted with a password, the browser cannot open it. Remove the password first, then compare the unlocked copies.

Small documents compare in 1 to 3 seconds. A 100-page contract may take 10 to 20 seconds depending on your device. You will see progress while both files are read.

Text extraction works for most languages, but line alignment can be less accurate for right-to-left scripts. Check the flagged lines carefully for Arabic, Hebrew or Urdu documents.

No. Both files are opened read-only in memory. The originals on your device are never modified.