Text Diff Checker — Compare Two Texts & Find Differences Free
Compare two texts and highlight differences online free — additions, deletions and changes clearly marked. No sign-up, no uploads, runs entirely in your browser.
Last updated: June 2026
Original text
Modified text
Diff level
About this tool
How to compare two texts online
When two versions of something look almost identical, spotting what actually changed by eye is slow and error-prone. A text diff checker does it for you: paste the original and the modified text, and it highlights every insertion and deletion so the changes jump out instantly.
This tool compares at three levels. Word mode is the most readable for prose; character mode catches the smallest edits like a single changed digit; and line mode is ideal for code and lists. Whichever you choose, you get a clear add/remove count and a similarity percentage to gauge how much changed overall.
The whole comparison runs in your browser, so neither text is uploaded — safe for contracts, drafts and source code alike. Copy the combined diff as text, or use the header Share button to send a link with both versions encoded (best for non-sensitive content). Comparing structured data? Tidy it first with the JSON formatter for a cleaner line-by-line diff.
How it works
Three quick steps — no account, nothing uploaded to a server.
Paste your text
Type or paste your text into the box.
Compare the texts
See added, removed and changed content highlighted.
Use your results
Copy the output or download it.
FAQ
Frequently asked questions
How does the diff checker work?
Paste your original text on the left and the changed version on the right, then click Show Diff. The tool runs a longest-common-subsequence comparison in your browser and renders a single combined view: additions are highlighted in green, deletions in red with a strike-through, and unchanged text is left plain. It also reports words added, words removed and an overall similarity percentage.
What's the difference between word, character and line mode?
Word mode compares text word by word — best for prose and the easiest to read. Character mode compares letter by letter, useful for spotting tiny edits like a changed digit or typo. Line mode compares whole lines, which suits code, lists and structured text where you care about which lines changed.
Is my text kept private?
Yes. The comparison runs entirely in your browser with JavaScript, so neither text is uploaded or stored on a server. You can safely compare confidential documents, contracts or code. The only exception is if you use the Share button, which encodes the texts into the page URL — only use that for non-sensitive content.
Can I share a comparison?
Yes. The Share button in the header copies a link with both texts encoded in the URL (each capped at 1,000 characters), so the recipient sees the same comparison when they open it. For longer or sensitive text, copy the diff output as text instead.
What can I do with the result?
You can read the inline highlighted diff, check the add/remove and similarity stats, copy the combined diff as plain text, swap the two sides, or clear both boxes to start over. Switch diff modes at any time and the comparison re-runs instantly.
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