Enter text and choose an action.
Result
Method and worked example
The comparison uses a bounded Myers sequence-difference algorithm. It finds a deterministic edit script without allocating a full length-by-length matrix. If an unusually high edit distance reaches the safety bound, a linear prefix-and-suffix fallback produces a valid, reconstructable comparison rather than locking the browser.
Example
Compare “Keep this line.\nOld wording.” with “Keep this line.\nNew wording.” The shared line is unchanged, the old line is removed, and the new line is added.
Limits and interpretation
Line mode accepts up to 1,000,000 characters per side. Word mode accepts 250,000 per side. Both modes stop at 50,000 tokens, and the edit search is bounded at 1,200 steps. Comparison settings affect matching only; displayed source text is never silently rewritten.
Safe local processing
All submitted content is treated as plain text. The tool uses text nodes and safe DOM APIs for results. It does not render pasted markup, call an AI service, request a remote text-processing API, or store drafts for later use.