About the Compare PDFs
Tezmy's Compare PDFs tool reads the text of two versions of a document and shows exactly what changed: lines that were added, removed or edited, side by side, with the page each line is on and the changed words highlighted. It's a quick way to check a new version of a contract, quote, policy or report without reading both from start to finish. It compares the words only, not the layout or pictures, and it all runs in your browser, so neither file is uploaded.
Updated October 2026
How to use the Compare PDFs
- 1Click Select PDF files and pick the original PDF, then the changed one (or both at once).
- 2Check the files are in the right boxes; click Swap if they're the wrong way round.
- 3Click Compare PDFs.
- 4Read the changes: removed text on the left in red, new text on the right in green.
- 5Switch to Everything to see the full text with the changes in place.
When to compare two PDFs
- A contract, lease or offer letter comes back with “a few small changes”.
- A supplier sends an updated quote or price list and you want to see what moved.
- A policy, terms of service or handbook has a new version.
- You're checking that corrections to a report or thesis were actually made.
- Two copies of a document exist and you're not sure which is the latest.
How to read the results
The summary at the top counts lines added, removed and unchanged. Below it, each row shows the original on the left and the changed version on the right. Red means text that was removed or replaced; green means new text. Inside a changed line, the exact words that differ get a stronger highlight, so a changed price or date stands out straight away.
The p. number next to each line is the page it's on in that file, so you can find it in the PDF. Only changes (the default) shows each change with a couple of unchanged lines around it for context and folds long unchanged stretches into a single “unchanged lines” bar. Choose Everything to read the full text with the changes in place. On a phone the two sides are stacked instead of side by side.
What it compares, and what it doesn't
The tool reads the text layer of each PDF, the same text you can select and copy, and compares it line by line. That makes it good at finding changed words, numbers, names and clauses. It does not look at pictures, logos, signatures, colours, fonts or page layout, so a document can look different and still count as the same text.
Blank lines are ignored, and Ignore extra spaces (on by default) stops spacing differences from counting as changes. Because a PDF stores text in lines as it appears on the page, adding a word near the start of a paragraph can push the words after it onto the next line, and those lines then show as changed as well.
Tips for a clean comparison
- Put the older version in the Original box. Removed text is then shown as removed, not as added.
- If a PDF has no text, it's a scan. Compare an original digital version instead if you can get one.
- To compare text you've copied from somewhere else, such as an email or a web page, use Diff Checker.
- Only need the text of one PDF? PDF to Text copies it out in one click.
On a phone or computer, and private
It works in any modern browser on iPhone, Android, Windows and Mac, with nothing to install. A computer's wider screen shows both versions side by side, which is easiest for long documents. Both PDFs are read on your own device and never uploaded, so it's safe for contracts, HR letters and financial documents. Need just one file out of two? Merge PDF puts them in order, and Diff Checker compares plain text you pasted.
Features
- Side-by-side view of added, removed and changed lines
- Changed words highlighted inside each line
- Page number next to every line
- Only changes view hides unchanged text
- Ignore extra spaces and ignore case options
- Private: files never leave your device
Frequently asked questions
How do I compare two PDF files for differences?
Select the original PDF and the changed PDF, then click Compare PDFs. The tool reads the text of both and lists every line that was added, removed or changed, with the page number and the changed words highlighted.
Does it compare images, layout or formatting?
No. It compares the text only. Changes to pictures, colours, fonts, bold or italic, or where things sit on the page won't show up. If a new version only moved text around on the page without changing the words, the tool will say the text is the same.
Can I compare scanned PDFs?
Not directly. A scanned PDF is a picture of each page, so there's no text to compare, and the tool tells you when that happens. Scans need text recognition (OCR) first.
Why does a whole line show as changed when only one word is different?
The comparison works line by line, then highlights the words that differ inside a changed line. Look for the darker highlight: that's the part that changed. When a small edit makes a paragraph wrap differently, the following lines of that paragraph can show as changed too.
What do Ignore extra spaces and Ignore case do?
Ignore extra spaces treats one space and several spaces as the same, which avoids false changes caused by how PDFs store spacing; it's on by default. Ignore case treats capital and small letters as the same, so “Total” and “TOTAL” match.
Can I compare two versions of a contract?
Yes, that's a common use. It quickly shows changed amounts, dates, names and clauses. It's a helpful check, not legal advice, so for important agreements still read the final version carefully.
Is there a size limit?
There's no file size limit, but long documents take a little longer to read. If the two PDFs are almost completely different (for example two unrelated documents), the tool says they're too different to compare line by line.
Are my PDFs uploaded?
No. Both files are read and compared in your browser. Nothing is sent to a server, which matters for contracts and other private documents.