Text Diff Checker — Compare Text Online
Compare two texts and see the differences highlighted — instant and private.
How to Use Text Diff Checker
Paste original text on the left
Paste modified text on the right
See a colorized diff with line numbers
Your files never leave your browser
No upload wait time. Results in seconds
No daily limits, no file count limits
No account, no subscription, no fees
About Text Diff Checker
The diff checker uses the Longest Common Subsequence (LCS) algorithm — the same approach behind Git's diff output — to find the minimum set of changes between two texts. Lines that exist only in the original are shown as removed, lines only in the modified version as added, and matching lines as unchanged.
Common Use Cases
- Comparing code before and after refactoring
- Checking document version changes
- Reviewing config file modifications
- Finding differences between translated texts
Frequently Asked Questions
How does the diff algorithm work?
It uses the Longest Common Subsequence (LCS) algorithm to find the minimal set of changes between the two texts — the same approach used by Git.
Is there a size limit?
For best performance, keep texts under 5,000 lines. Larger texts may take a moment to compute.