Text Diff Checker
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Compare two texts line by line with word-level highlighting — and get told about the differences you can't see: CRLF vs LF line endings, a missing final newline, trailing whitespace. All in your browser, nothing uploaded.
How it works
- Line-level diff uses Myers’ algorithm — the same one behind
git diff— so it finds the smallest set of added and removed lines. A removed line followed by an added one at the same spot is shown as one modified line, with the exact words that changed highlighted. - Long runs of unchanged lines are folded down to 3 lines of context on each side of a change, like a code review. Click a fold to expand it.
- Ignore whitespace treats indentation and spacing changes as equal (a reformatted file stops looking 100% changed); Ignore case does the same for capitalization.
The differences you can’t see are named, not shown as noise. The same file saved on Windows (CRLF line endings) and on macOS/Linux (LF) differs on every single line, so a naive diff marks the whole file as changed and leaves you hunting for a difference that isn’t visible. Here, line endings are normalized before comparing and reported in a note instead. A missing newline at end of file and lines that differ only in trailing spaces are called out by name too. And when the ignore options make two texts match that aren’t byte-for-byte equal, the result says so — “identical” never quietly means “identical after we threw some of it away”.
Inputs are capped at 20,000 lines per side. Two texts with more than 2,500 changed lines get a clear error instead of a frozen tab — at that point they’re different documents, not two versions of one.
Runs entirely in your browser — nothing you paste here is uploaded, logged, or stored.