Text diff checker

How to use this tool

1. Paste the original text on the left and the changed text on the right.
2. Choose whether to compare by word, by line or by character.
3. Read the highlighted result: additions in green and removals in red.
4. Copy the summary or use the counts of added and removed items.

How it works

The checker finds the longest run of text the two versions share and marks everything else as removed or added. It first trims the beginning and end that are identical, then compares the middle, so even long documents with small edits are fast.

Word mode is best for prose and contracts, line mode for lists and code, character mode for catching a single changed digit. The comparison runs entirely in your browser, so confidential drafts stay on your device.

Good to know

A diff shows exactly what changed between two versions. It is useful for contracts and policy updates, edited articles, translations, configuration files and code snippets. Word mode suits prose, line mode suits lists and code, and character mode helps find a single changed letter, such as in a license key or a number.

Both texts stay in your browser, so you can compare confidential drafts. Differences in spaces and capitalisation can be hard to see by eye, which is why a character-level comparison is the fastest way to find a subtle edit.