Text Compare
Paste two texts to see exactly what changed. Added words turn green, removed words red, with a similarity score.
Quick Answer
When to Use a Text Comparison Tool
A text compare tool answers one question fast: what changed between two versions? Instead of re-reading both texts line by line, you see additions and deletions highlighted in color, plus a single similarity number that tells you how much of the original survived.
This is useful any time you have two drafts of the same writing. Students compare a draft against an instructor's edited version to learn what was cut. Writers check what an editor or co-author changed. Professionals confirm which clauses moved between two versions of a contract or policy. And anyone reviewing AI-assisted edits can see exactly which words the model added or removed.
Because the comparison is word-level, the highlights stay readable: you see whole words change rather than a noisy stream of single-character differences. That makes it the right fit for prose rather than source code.
How to Read the Result
| Signal | Meaning |
|---|---|
| Green word | Inserted in the changed version (not in the original). |
| Red strikethrough word | Removed from the original (not in the changed version). |
| Plain word | Unchanged between both versions. |
| Similarity 100% | The two texts are identical. |
| Similarity 0% | The two texts share no words in common order. |
| Side-by-side view | Shows the original (with deletions) and the changed text (with insertions) in two columns. |
Similarity uses the Sorensen-Dice coefficient on word tokens: twice the shared words divided by the total words in both texts.
Who Uses Text Compare?
🎓 Students & Researchers
Compare a draft against feedback to see exactly what an instructor or reviewer changed, then learn from the edits.
✍️ Writers & Editors
Track changes between drafts and confirm an editor's revisions without re-reading the whole piece.
📄 Professionals
Spot which clauses or sentences moved between two versions of a contract, policy, or proposal.
🤖 AI-Assisted Writers
See precisely which words an AI rewrite added or removed before accepting the changes.
Paste your original text on the left and the changed text on the right. The tool runs a word-level comparison and highlights inserted words in green and removed words in red, with a similarity percentage so you can see at a glance how much changed. The comparison updates instantly as you type.
No. The comparison runs entirely in your browser using JavaScript. Your text never leaves your device, which keeps confidential drafts, contracts, and documents private. The tool also works offline once the page has loaded.
Similarity is the share of words the two texts have in common, calculated as twice the number of matching words divided by the total words in both texts (the Sorensen-Dice coefficient). 100% means the texts are identical; 0% means they share no words in the same order.
Word-level diff treats whole words as the unit of comparison, which is the right choice for prose, essays, emails, and documents because it produces readable, meaningful highlights. Character-level diff is used mainly for source code. This tool uses word-level comparison.
The tool compares two texts at a time. To compare a third version, replace one side with the new text and run the comparison again. Comparing pairs in sequence is the standard way to track changes across multiple drafts.
The diff is based on the longest common subsequence, so it aligns matching words in order. A block of text that is moved elsewhere will usually show as a deletion in the old position and an insertion in the new position, which is the expected behavior for a word-level comparison.
Yes. It is 100% free with no signup, no limits, and no ads interrupting the result. Everything runs in your browser.
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Sources & References
- The diff is computed with a longest common subsequence (LCS) alignment over word tokens, the standard algorithm behind text-comparison and version-control diff tools.
- The similarity percentage uses the Sorensen-Dice coefficient (Dice, 1945; Sorensen, 1948), a common measure of overlap between two sets.
- Word-level (rather than character-level) comparison follows the convention used by document-comparison features in word processors, where whole-word changes are more meaningful to readers.