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Compare two texts and highlight differences instantly. Nothing leaves your browser.
The Diff Checker compares two blocks of text and highlights exactly what changed — added, removed, and unchanged lines — so you can spot edits between versions of a document, config, or snippet at a glance.
It's the quick, private alternative to a full version-control diff when you just need to compare two pastes.
The tool aligns the two texts and marks each line as added, removed, or common, using a line-based comparison similar to standard diff algorithms. The colour-coded output makes insertions and deletions obvious without reading both versions in full.
All comparison runs locally, so you can diff sensitive documents without uploading them anywhere.
Paste two versions of a config file and the checker highlights the three lines that changed, saving you from scanning hundreds of identical lines to find the edit.
Primarily line-by-line, which suits documents, configs, and code.
No — the comparison runs entirely in your browser.
Yes, within practical browser limits.
Yes — added, removed, and unchanged lines are all shown and colour-coded.
Yes — 25 languages, no sign-up.