Text Diff Checker
Paste an original and a changed version to see exactly what changed — every added line in green, every removed line in red. It runs entirely in your browser, so your text stays private.
How to compare two texts
- Paste the original text on the left.
- Paste the changed text on the right.
- Read the highlighted result — added lines in green, removed lines in red.
About text diffing
A diff compares two pieces of text line by line and shows what was inserted, deleted or left unchanged — the same idea behind code review and version control. It is the fastest way to spot what changed between two drafts, two config files, or two copied-and-pasted blocks.
This tool computes a line-level diff using a longest-common-subsequence match, so unchanged lines line up and only genuine changes are highlighted. Everything is calculated in your browser — no account, no upload — which makes it safe for comparing private documents, contracts or code.
Frequently asked questions
Is my text uploaded?
No. The comparison runs entirely in your browser, so both texts stay on your device — safe for private or confidential content.
Does it compare line by line or word by word?
It compares line by line: each line is marked added, removed or unchanged. To compare a single sentence, put each part on its own line.
Is there a size limit?
Very large inputs (thousands of lines each) are capped so your browser stays responsive; for typical documents and code there is no practical limit.
Can it compare code?
Yes. Any plain text works, including source code, JSON, CSV or logs — paste both versions and the changed lines are highlighted.