Compare two texts and spot every difference instantly. Paste your original and modified versions to see added words highlighted in green and removed words struck through in red — free, unlimited, and no sign-up needed.
Tip: the diff is word-based, so moved sentences show as removed in one place and added in another.
How to use the Text Diff Checker
- Paste your original version into the first box and the modified version into the second box.
- Click Compare Texts to run a word-level comparison.
- Review the result: removed words appear in red with strikethrough, added words in green, with totals for added, removed, and unchanged words.
Frequently asked questions
How does the comparison work?
The tool splits both texts into words and runs a longest-common-subsequence diff, the same family of algorithm used by code review tools. Unchanged words stay plain, deletions are marked red, and insertions are marked green.
Is there a size limit?
Very large documents (roughly over 1,400 words per side) are rejected to keep your browser responsive. For best results, compare one section at a time.
Is my text uploaded anywhere?
No. The entire comparison runs locally in your browser with JavaScript. Your text never leaves your device.