Text Diff Checker
Compare two blocks of text line by line and highlight what was added and removed. Fast, private, in your browser.
Move detection is not performed; moved text appears as removed and added.
Limits per side: 200,000 characters · 20,000 lines · 100,000 word or grapheme units. Time budget: 300 ms; grapheme granularity gets 2,000 ms and falls back to word granularity on timeout. Oversized comparisons show no partial result.
Structured JSON? JSON diff checker · find/replace: Find & replace · dedupe lines: Remove duplicate lines.
FAQ
How does it compare?
It uses a bounded Myers diff in a background worker, with line, word and grapheme comparison modes.
Is my text uploaded?
No. The comparison runs entirely in your browser.
JSON diffs?
For structured data, use the json diff checker — this tool is best for plain text and config files.
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