Text Compare
Word- and character-level diff, accurate for Korean and CJK text — all in your browser, no limits.
- Runs in your browser — files never leave your device
- Features others lock behind paywalls
- More accurate results
Saved in this browser only
Enter text in both boxes to see what changed.
How to use
- Paste or type the original text on the left.
- Paste the edited version on the right.
- Choose Line, Word or Character comparison mode.
- Added text is highlighted in green, removed text in red.
- Click Swap to compare the two texts in the other direction.
Which comparison mode should I use?
Line mode is best for code, logs or long documents, since it shows which whole lines were added, moved or removed. Word mode is best for prose: it highlights only the words that actually changed, so editing a single word doesn't make the whole sentence look different. Character mode is the most precise — useful for comparing IDs, URLs or phone numbers, where a single changed character matters.
Why this diff stays accurate for Korean and CJK text
Many browser-based diff tools split text by raw UTF-16 code units, which can cut emoji and combining characters in half. This tool segments text into user-perceived characters (Unicode grapheme clusters) instead, so a Hangul syllable or a multi-codepoint emoji is always treated as one unit. Text is also normalized to NFC before comparing, so Korean text whose jamo were decomposed into separate combining characters (NFD) — a known side effect of passing through macOS's filesystem — compares as identical to the same text typed normally, instead of showing a false difference on every character.
What "added", "removed" and "similarity" mean
"Added" and "removed" count the tokens (lines, words or characters, depending on the mode) that differ between the two texts. "Similarity" is the share of tokens the two texts have in common, calculated as twice the number of matching tokens divided by the combined length of both texts — 100% means the texts are identical, 0% means they share nothing at all.
Frequently asked questions
Does this tool upload my text anywhere?
No. Every comparison runs in your browser using JavaScript; the two texts are never sent to a server, logged, or stored anywhere outside your device's local storage.
What's the difference between line, word and character mode?
Line mode compares whole lines, word mode compares individual words plus the spaces and punctuation between them, and character mode compares every user-perceived character one by one, including emoji and accented letters.
Why do two identical-looking Korean texts sometimes show as different?
Some systems store Hangul with its jamo (letters) decomposed into separate Unicode characters instead of combined into whole syllables — a common side effect of text that passed through macOS's filesystem. This tool normalizes both texts before comparing, so visually identical Korean text always compares as identical.
Can I compare two whole documents, or just short text?
Either works. Paste anything from a single sentence to a multi-page document; the comparison updates as you type for typical document lengths, though very large files take a moment longer on slower devices.
Is there a limit to how much I can compare?
No. There's no sign-up, no daily limit, and no feature paywalled behind a paid plan — word- and character-level comparison are both free and unlimited.
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Updated 2026-10-11