Text Diff
Compare two blocks of text line by line, in a split or unified view. Nothing leaves your browser.
Lines are matched with a longest-common-subsequence diff. A changed line shows as a removal on the left paired with an addition on the right.
About the Text Diff
Paste two versions of a block of text and this tool highlights exactly what changed between them, line by line. It is the same idea as a code review diff, but for anything: two drafts of an email, two config files, a copied-and-pasted log before and after, or two API responses you suspect differ in one subtle place.
You can view the comparison side by side in a split layout or stacked in a unified layout, and you can tell it to ignore case or whitespace differences when those do not matter. Added, removed and unchanged lines are counted and colour-coded, so the shape of the change is obvious at a glance.
How to use it
- Paste the original text on one side and the changed text on the other.
- Choose the split view to see the two versions next to each other, or the unified view to see them stacked.
- Turn on ignore-case or ignore-whitespace if those differences are noise for your comparison.
- Read the highlighted additions and removals, and the per-side line numbers.
Good to know
- Split and unified views, with a swap button to flip the two sides.
- Options to ignore case and whitespace.
- Line counts for additions, removals and unchanged lines.
- Runs entirely in your browser; nothing you compare is uploaded.
Frequently asked questions
What is the difference between the split and unified views?
The split view puts the two texts side by side and lines up their changes. The unified view stacks them into one column, showing removed lines followed by the added lines that replace them — the style you see in most code review tools.
Can it ignore formatting-only differences?
Yes. Turn on ignore-whitespace to treat lines that differ only in spacing or indentation as identical, and ignore-case to treat upper and lower case as the same. This keeps the diff focused on meaningful changes.
Is there a size limit?
The comparison is designed for two revisions of a document, which it handles instantly. Extremely large inputs will still work but take longer, since comparing lines is inherently more work as the texts grow.
Is my text kept private?
Yes. The whole comparison runs locally in your browser. Neither block of text is uploaded, so it is safe for private documents and logs.