Is this a character-level or line-level diff?

The viewer shows line-level changes, which is usually what you want for code and config review.

Are my pasted files sent anywhere?

No. Diffing runs entirely in your browser — nothing is uploaded or stored.

Is there a size limit?

There is no fixed limit. Very large files (tens of megabytes) may slow the browser since everything stays in memory.

$diff-checker

Testers

Compare two blocks of text and see the differences highlighted line by line. Added lines in green, removed lines in red. Everything runs in your browser.

Original

Modified