Text Diff Checker
Compare two blocks of text and highlight what changed, line by line.
Last updated August 26, 2026
About this tool
Comparing two versions of a document, config file, or piece of code by eye is tedious and error-prone for anything longer than a few lines. This tool computes a line-by-line diff using the same longest-common-subsequence approach behind tools like `diff` and `git diff`, highlighting exactly which lines were added, removed, or left unchanged.
Frequently asked questions
Does this diff at the word level or the line level?
Line level — a line with even a single character changed shows as one removed line and one added line, rather than highlighting the specific word that changed.
Is my text uploaded anywhere to compute the diff?
No, the comparison runs entirely in your browser.
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