How to use
- Paste the original text on the left and the changed version on the right.
- Choose how to compare — by line for code and lists, by word for prose, by character for short strings like IDs.
- Read the differences — removed text is red, added text is green — with a count of changed lines or characters.
- Download the result as a unified .patch file if you want to apply it with git or patch.
Options explained
- Lines
- Compares whole lines, like git diff. Side-by-side view pairs each removed line with its replacement.
- Words
- Highlights changed words inside lines — best for edited paragraphs and contracts.
- Characters
- Shows single-character changes, useful for spotting a typo in a key, hash or URL.
- Ignore case / spaces
- Treat "Hello" and "hello", or lines that differ only in leading and trailing spaces, as equal.
Examples
Code review without git. Paste the old and new version of a config file to check exactly which settings changed before deploying.
Contract revisions. Compare two drafts by word to see every edited phrase, including changed numbers and dates that are easy to miss.
Spot the typo. Two API keys that look identical but fail? Compare by character and the one differing character is highlighted.
Frequently asked questions
Is there a size limit?
No fixed limit. Texts of a few thousand lines compare instantly; very large files with many changes can take a second or two because the diff runs on your device.
Are my texts stored or uploaded?
No. Both texts stay in your browser tab and disappear when you close it.
What algorithm is used?
The Myers diff algorithm (the same family git uses), via the open-source jsdiff library. It finds the smallest set of additions and removals that turns one text into the other.
Can I compare Word or PDF files?
Copy the text out of the documents and paste it here. Formatting is not compared, only the text.
Why does a moved paragraph show as removed and added?
Diff algorithms describe changes as insertions and deletions in order, so a block that moved appears deleted in one place and inserted in another.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.