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JSON Diff Checker
Compares two JSON documents structurally and lists every added, removed and changed key path.
Code Diff Checker
Compares two code files line by line with syntax-aware whitespace handling and a unified diff output.
Developer
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No sign-up
Free, unlimited
Fill in both boxes to compare them.
In short
Code Diff Checker is a free online tool on inputtesthub.com that compares two code files line by line with syntax-aware whitespace handling and a unified diff output. It needs no account, no download and no payment, and there is no daily usage limit. Everything is processed inside your own browser, so the data you paste is never uploaded to a server.
How to use the Code Diff Checker
- Paste the original text into the first box.
- Paste the version you want to compare into the second box.
- Differences are highlighted immediately, line by line and word by word.
About the Code Diff Checker
The Code Diff Checker compares two code files line by line with syntax-aware whitespace handling and a unified diff output. It runs as plain JavaScript inside the page, which means there is no upload step, no queue and no size limit imposed by a server — the only limit is your own device.
What people use it for
- Reviewing a change before committing.
- Comparing a config file against a backup.
- Checking what a formatter altered.
Frequently asked questions
Are there any usage caps on the Code Diff Checker?
There is no cost and no cap. The Code Diff Checker is not a demo of a paid product, so nothing is held back or watermarked.
Can you see what I put into this utility?
No. The Code Diff Checker runs entirely in your browser using JavaScript. Your input never reaches inputtesthub.com or any third party — open your browser's Network tab while you use it and you will see no request go out.
Who is the Code Diff Checker for?
Typical uses: reviewing a change before committing. Comparing a config file against a backup. Checking what a formatter altered. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Is there an app version?
Yes. The page is responsive and the utility works in Chrome, Safari, Firefox, Edge and Samsung Internet on both Android and iOS. There is no app to install and nothing to sign into.
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