What can I do with Diff Checker?

Compare two texts side by side with line-level changes. Diff Checker is part of the Developer shelf on utils.sbs and is designed for quick, one-off tasks.

Is Diff Checker free to use?

Yes. Diff Checker is free, requires no account, and has no per-file or per-use charge.

Are my files uploaded when I use Diff Checker?

No. Diff Checker is designed to process your input locally in the browser. Files are not uploaded to a server for processing.

What formats does Diff Checker support?

It works with plain text, code, markup and structured text, and returns a downloadable text file.

Can I use Diff Checker on my phone?

Yes. Diff Checker is responsive and works in modern mobile browsers. Very large files may be limited by the device's available memory.

Developer tool

Diff Checker

Compare two texts side by side with line-level changes.

Runs on-deviceNo sign-upFree

All developer tools

Workspace

Diff Checker

Runs locally

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The guide

By the utils.sbs team · Reviewed November 2026 · How we build and review tools

Quick answer

Diff Checker is a free browser-based developer tool. Compare two texts side by side with line-level changes. It runs with JavaScript locally, requires no account and does not upload your files. Open the page, add your input, adjust any options and download the result.

What is Diff Checker?

Diff Checker is a free browser-based developer tool from utils.sbs. Compare two texts side by side with line-level changes. It is built for quick, focused jobs: open the page, add your input, adjust the options and take the result with you. No account, install or server upload is required.

At a glance

Category	Developer
Input	Plain text, code, markup or JSON
Output	A downloadable text or code file
Engine	JavaScript
Processing	In your browser
Price	Free
Account	Not required

How Diff Checker works

Text is processed in the browser with JavaScript and downloaded from a local blob. Nothing is uploaded.

How to use Diff Checker

1Open Diff Checker and add your input.
2Use the default settings, or choose the format or detail level that matches your goal.
3Run the tool, check the preview or result, and download the output.

When to use Diff Checker

Clean, transform or compare text before using it elsewhere.
Convert markup, JSON or structured text between formats.
Count, format or inspect content quickly in the browser.

Limitations

Very large inputs may be limited by the browser's available memory.

Privacy and accuracy

Diff Checker processes its input in the browser whenever the platform API allows it. Files and values are not uploaded to a server for processing, and the tool does not require an account. For calculations, use the result as a reference and verify important decisions against the source formula or a qualified professional. Read our methodology.

FAQ

Diff Checker questions

What can I do with Diff Checker?
Compare two texts side by side with line-level changes. Diff Checker is part of the Developer shelf on utils.sbs and is designed for quick, one-off tasks.
Is Diff Checker free to use?
Yes. Diff Checker is free, requires no account, and has no per-file or per-use charge.
Are my files uploaded when I use Diff Checker?
No. Diff Checker is designed to process your input locally in the browser. Files are not uploaded to a server for processing.
What formats does Diff Checker support?
It works with plain text, code, markup and structured text, and returns a downloadable text file.
Can I use Diff Checker on my phone?
Yes. Diff Checker is responsive and works in modern mobile browsers. Very large files may be limited by the device's available memory.

Keep going

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