Text compare tool
Paste two texts to see line-by-line differences with word-level highlighting. Click ← or → to merge changes. Free, private, runs entirely in your browser.
Text compare tool
Original
1
Modified
1
Tip: press Ctrl + Enter in either box to compare.
Original
Modified
How to use
- Paste your original text on the left and your modified text on the right. Line numbers update as you type.
- Click Compare (or press Ctrl+Enter). Differences appear below in side-by-side diff view.
- For changed lines, the specific words that differ are highlighted: removed on the left, added on the right.
- Hover any changed line and click → to push it to the right, or ← to push the modified line back to the left.
Diff colour key
| Colour | Meaning |
|---|---|
| Green | Line added (only on the right side) |
| Red | Line removed (only on the left side) |
| Yellow | Line changed — word-level highlighting shows what differs |
| Grey | Empty placeholder (keeps both sides aligned) |
Comparison options
- Case-sensitive — on by default. Turn off to treat “Hello” and “hello” as the same.
- Ignore whitespace — turn on to ignore tabs, spaces, and indentation differences.
- Ignore blank lines — skip empty lines from both texts before comparing.
FAQ
Is my text uploaded anywhere?
No. Everything happens in your browser. Your text never leaves your device — no servers, no logging, no analytics.
What's the largest text I can compare?
The diff algorithm is O(m×n). Comparing 5,000 lines vs 5,000 lines runs in under a second. Beyond ~20,000 lines per side, the browser may slow down — split your text into chunks if needed.
Does it diff at the word level inside a changed line?
Yes. Lines that change are diffed at the word level too, so you can see exactly which words were modified.
Can I export the diff?
Not directly, but you can copy the merged result from either textarea after applying merges.