Text Diff Checker
Compare two pieces of text and visualise added, removed and changed lines side-by-side.
Compare two pieces of text and visualise added, removed and changed lines side-by-side.
This free Text Diff Checker from KX Toolkit is part of our all-in-one online toolkit. It runs entirely in your browser, so your data never leaves your device for client-side operations. 100% free, forever - no paywall, no credit card, no trial.
How to use the Text Diff Checker
- Paste your input - JSON, regex pattern, JWT, URL etc.
- Pick any flags or options the tool supports.
- Click the action button (Format, Test, Decode).
- Copy the result or download it as a file.
What you can do with the Text Diff Checker
- Format and validate API responses while debugging.
- Test regex patterns against real input before deploying.
- Decode JWTs to inspect claims and expiry.
- Generate UUIDs for migrations, tests and seeders.
Why use KX Toolkit's Text Diff Checker
- Browser-based: Works on Windows, macOS, Linux, iOS and Android - no install, no extension.
- Privacy-first: Client-side tools never upload your data; server-side tools delete files right after processing.
- Mobile-friendly: Full feature parity on phones and tablets - not a stripped-down view.
- Fast: Optimised for instant feedback. No artificial waiting screens, no email-gated downloads.
- One hub for everything: 300+ tools across SEO, text, image, PDF, code, color, calculators and more - skip switching between sites.
Tips for the best results
Bookmark the most-used tools - your browser bookmark bar is faster than retyping the URL every time.
Related Developer Tools
If you find this tool useful, explore the full Developer Tools collection or browse our complete tool directory. KX Toolkit is built for marketers, developers, designers, students and anyone who needs a quick utility without signing up for yet another SaaS.
What is the difference between line diff and character diff?
Line diff compares whole lines and highlights ones that changed; it works well for source code where each statement usually lives on its own line. Character diff goes finer, showing exactly which letters or words changed within a line, which is helpful for prose, configuration values, and one-line strings. Many tools combine the two - line diff first, then character diff inside changed lines.
How do I compare files that have different line endings?
Normalize line endings before diffing or enable the tool's ignore-line-endings option. Otherwise CRLF on Windows files and LF on Unix files will mark every single line as changed. Git can also normalize via the autocrlf and core.eol settings. For ad-hoc comparisons, a quick search-and-replace of \r\n with \n handles it cleanly.
Why does the diff sometimes look weird around moved blocks?
Standard diff algorithms are line-based and treat a moved block as a deletion plus an addition, even though no content changed. Tools that use the Patience or Histogram algorithms produce nicer hunks for refactored code. If a tool offers a moved-detection option, enable it for clearer reviews of large reorganizations.
Can I ignore whitespace or case differences?
Most diff viewers expose options to ignore leading or trailing whitespace, ignore changes in amount of whitespace, and ignore case. These flags reduce noise from formatter changes and renamed identifiers. Use them when reviewing intent rather than literal bytes; turn them off for security-sensitive comparisons where every byte matters.
Is my pasted text sent to a server?
In-browser diff tools compute the diff locally using a JavaScript implementation of Myers or Patience, so the text never leaves your tab. Web-based diff services that show share links must transmit the content. Read the privacy notice before pasting confidential code or contracts; any tool that lets you generate a public URL of the diff is uploading the data.
How do I diff structured data like JSON or YAML?
Format both inputs with the same indentation and key order first, then run a text diff. Even better, use a structural diff tool that understands the format - jq with --sort-keys for JSON, deep-object-diff in JavaScript, or Beyond Compare with a YAML plugin. Structural diff suppresses noise from formatting and key reordering that text diff cannot handle.
No reviews yet
Be the first to share your experience with the Text Diff Checker.