Online Diff Checker for Code & Text
Paste two versions of your code or text and instantly see what changed, line by line. This diff tool runs entirely in your browser — no data is uploaded to any server, ever.
Code Diff Checker
Compare two pieces of text or code to see structural differences.
What is a diff checker?
A diff checker compares two versions of text or code and highlights exactly what changed — additions, deletions, and modifications. Developers use it to review code changes, catch bugs, and understand the difference between two config files or API responses.
Why use this online diff tool?
Most diff tools either require installation or send your code to a remote server. This tool is different: everything runs locally in your browser. That means you can safely compare confidential code, credentials, or private configs without worrying about leaks.
It works on any device, instantly — no downloads, no accounts, no waiting.
How to compare two files or code snippets
- Paste your original text or code in the left panel
- Paste the modified version in the right panel
- Click Compare — differences are highlighted instantly
- Green lines are additions, red lines are deletions
Why this diff checker is better for privacy
Unlike server-based diff tools, your data never leaves your browser. There are no logs, no analytics on your input, and no third-party processing. Ideal for comparing sensitive source code, environment files, or API responses.
Frequently Asked Questions
Can I compare source code with this?
Yes. It works with any plain text — JavaScript, Python, JSON, YAML, HTML, SQL, or prose.
Does this tool send my code to a server?
No. The diff runs entirely in your browser using JavaScript. No data is transmitted anywhere.
How are differences shown?
Added lines are shown in green, removed lines in red, and unchanged lines in grey. This makes it easy to spot changes at a glance.
Is this tool free?
Yes. Completely free, no registration required.