TEXT diff
readyPaste two blocks of text - see line-by-line additions and deletions. Useful for comparing config files, logs, JSON dumps, code, anything line-oriented.
Diff
[01] About this tool
This is a line-by-line diff using the longest-common-subsequence (LCS) algorithm - the same family of algorithm used by git diff, diff -u, and most code editors. It finds the smallest set of insertions and deletions that transforms the left text into the right one.
[02] What it doesn't do
- Word-level or character-level diff: only line-by-line. Two lines that share most words but differ slightly will both be marked changed.
- Three-way merge: only two inputs.
- Patch application: output is for reading, not for piping to
patch. Usegit applywith proper unified-diff headers for that.
[03] Privacy
Everything runs in your browser. The two text blocks never leave the page - no logging, no analytics on the content. Safe for diffing sensitive configs.
Common questions
Is Text Diff Tool free to use?
Yes. The tool runs in your browser at no cost, with no signup required.
Where is the math performed?
Calculations run locally in your browser. Your inputs do not leave your device.
Are the rates and rules current?
We update sources when published rates change. For high-stakes decisions, verify against the official source linked on this page.