Diff Checker is a 100% free, browser-based utility that enables you to compare two texts and highlight the differences. Unlike traditional cloud converters, all processing executes locally on your device with zero server uploads, delivering immediate results and ironclad data privacy.
About the Diff Checker
The Diff Checker compares an original and a changed version of any text, such as code, configuration files, contracts or articles, and highlights exactly what was added and removed. Switch between line, word and character comparison depending on how fine-grained you need the result to be.
Options let you ignore differences in whitespace or letter case, which is useful when comparing re-indented code or text with inconsistent capitalisation. Both texts stay in your browser, so it is safe for private code.
How to use the Diff Checker
- Paste the original text on the left and the changed text on the right.
- Choose whether to compare by lines, words or characters.
- Turn on "Ignore whitespace" or "Ignore case" if needed.
- Review the highlighted result: green is added, red is removed.
Features
- Line, word & character diff
- Ignore whitespace and case
- Added / removed statistics
- Swap sides in one click
Why Choose In-Browser Diff Checker vs Cloud Converters?
| Feature | Toolora (In-Browser) | Traditional Cloud Tools |
|---|---|---|
| Data Privacy | 100% Private (Files stay on device) | Uploaded to remote servers |
| File Size Limits | Unlimited (Limited only by your RAM) | Restricted (e.g. 10MB–50MB caps) |
| Processing Speed | Instant (Zero upload/download delay) | Slow upload & queue waiting |
| Ads & Popups | Clean, distraction-free | Heavy banner & interstitial ads |
Frequently asked questions
What algorithm is used to compare the texts?
The comparison uses the Myers diff algorithm (via the open-source jsdiff library), the same approach used by Git, which finds the smallest set of insertions and deletions between two texts.
When should I use word or character mode?
Line mode is best for code and structured files. Word mode is ideal for prose where a sentence changed slightly, and character mode shows tiny edits such as a changed digit or typo.
Are my texts uploaded to compare them?
No. The diff is calculated entirely in your browser, so confidential code and documents never leave your device.