Text Diff Checker
Compare two blocks of text and see line-by-line differences highlighted instantly — additions and deletions color-coded. Free, client-side diff tool.
🔒 100% Client-Side Processing
Your data is processed entirely in your browser and never transmitted to any server.
Frequently Asked Questions
- How does the diff checker compare the texts?
- It runs a longest-common-subsequence (LCS) diff over whole lines — the same family of algorithm behind git diff. Unchanged lines stay neutral, lines only in the original are marked removed (−), and lines only in the changed version are marked added (+).
- Why does a one-character edit show as a removed line plus an added line?
- The comparison is line-granular: any line that differs by even one character counts as a different line, so it appears as the old line removed and the new line added. This keeps the output unambiguous for code review and config comparison.
- What can I compare with a text diff?
- Two versions of a config file before deploying, API responses before and after a change, contract or document revisions, SQL schema dumps, and pasted code snippets — anywhere you need to spot exactly what changed between two versions.
- Is my data private when I use this tool?
- Yes. This tool runs entirely in your browser using client-side JavaScript — nothing you type is transmitted to, logged by, or stored on any server. You can safely process confidential text, tokens, or code.