What programming languages does the Diff Checker support?

All of them. The Diff Checker is language-agnostic and treats input as plain text, so it works equally well with JavaScript, Python, TypeScript, Ruby, Go, SQL, YAML, and any other language.

Can I compare minified code?

Yes, but the diff may be harder to read. For languages like CSS or JavaScript, it helps to format/prettify both files before comparing to get a more readable line-by-line diff.

Is this suitable for code review?

It is great for quick comparisons and spot-checking changes. For full code review workflows with comments and approvals, a dedicated code review tool or Git platform is more appropriate.

Can I compare entire files or just snippets?

Both. You can paste short snippets or the full content of larger files. There is no character limit imposed by FixTools.

Does the tool syntax-highlight the code?

The Diff Checker focuses on highlighting differences rather than syntax. Both versions are shown with change highlighting rather than language-specific syntax colouring.

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Free · Fast · Privacy-first

Compare Code Online — Any Language

Quickly compare two versions of any code snippet or file — JavaScript, Python, CSS, SQL, shell scripts, and more. FixTools Diff Checker highlights every added, removed, and modified line so you can review changes without switching to a full code editor.

⚡ Use Tool Now How it works

Cost: Free forever
Sign-up: Not required
Processing: In your browser
Privacy: Files stay local

⚡

Works with any programming or markup language

🔒

Line-by-line diff with colour-coded changes

✨

No IDE or software installation needed

Developer Tool

Diff Checker

All processing happens in your browser — your files are never uploaded to any server.

🚀Open Diff Checker

100% Free · No account · Works on any device

How to use this tool

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Paste two versions of your code into the left and right panels and click Compare. All line-level changes are highlighted immediately.

How It Works

Step-by-step guide to compare code online — any language:

1
Open Diff Checker
Click "Open Diff Checker" to launch the tool.
2
Paste original code
Paste the original version of your code into the left panel.
3
Paste updated code
Paste the modified version into the right panel.
4
Click Compare
Click Compare to run the diff. Changed lines are highlighted by type: green for additions, red for deletions.
5
Switch views if needed
Toggle between side-by-side and inline diff views depending on how you prefer to review the changes.