Text Diff Checker & Clean Utility
Compare two pieces of text side by side with word, line, or character diff highlighting, then normalize whitespace and punctuation with the bundled text cleaner. Powered by diff-match-patch — everything runs locally in your browser.
Compare two texts
Auto-runs as you type · 300 ms debounceHow to use
Two tabs: Diff Checker compares two texts and shows inline highlights; Text Clean normalizes whitespace, line endings, and punctuation. Each tab has a Load sample button.
- Choose a tab — Diff Checker for comparing two texts, Text Clean for normalizing one text.
- Load sample or paste — press Load sample to fill both panes (Diff) or the input pane (Clean) with realistic example data.
- Pick options — in Diff: mode (word / line / character), ignore whitespace, ignore case; in Clean: toggle the six normalization rules.
- Run — Diff auto-runs 300 ms after you stop typing; press Swap left & right to flip original and modified. Clean runs on button click.
- Copy — press Copy diff to copy the highlighted diff as plain text with
+/-markers, or Copy output for the cleaned text.
What it does
Word diff
Tokenizes both texts into words and whitespace, runs diff-match-patch, and reassembles with inline green additions and red strikethrough deletions.
Line diff
Encodes each line as a single character, diffs the encoded strings, and renders one block per line with full-line green/red backgrounds.
Character diff
Raw character-level diff with semantic cleanup. Best for spotting single-character edits inside words.
Similarity score
Percentage of matching characters over the longer text. Updates live with the diff.
Text cleaner
Six toggleable rules: trim per line, collapse spaces, drop empty lines, normalize CRLF to LF, dedupe trailing punctuation, and strip smart quotes.
Privacy
100% client-side. No paste is uploaded — verify in DevTools → Network. Only the diff-match-patch library loads from CDN on first visit.