100% private · runs in your browser
Diff Checker
Paste two versions of a text and see exactly which lines changed.
✓ Free forever✓ No sign-up✓ No watermark✓ Files never leave your device
How to use the Diff Checker
- Paste the original text on the left and the changed text on the right.
- Click Compare.
- Review the green (added) and red (removed) lines.
Added lines are green and removed lines are red, with line numbers for both versions. Turn on Ignore whitespace or Ignore case to skip small formatting differences. Comparison happens line by line in your browser.
Why use Toolbox
Private by designProcessing happens on your device. Nothing is uploaded to a server.
FastNo waiting for uploads or queues. Results appear instantly.
Works everywhereUse it on phone, tablet or desktop in any modern browser.
Truly freeNo account, no watermark and no hidden paywall.
Frequently asked questions
How does the comparison work?
It finds the longest set of lines both texts share and marks everything else as added or removed.
Can I compare code?
Yes. It works on any plain text, including code, configuration files and documents.
Is this tool really free?
Yes, always free with no sign-up, no watermark and no file limits set by us.
Are my files uploaded anywhere?
No. Everything happens inside your browser, so your files and text never leave your device.