What is a diff checker?

A diff checker compares two pieces of text and highlights the differences between them, showing what was added, removed, or changed.

What does the diff output mean?

Green lines were added in the new version. Red lines were removed from the original. White lines are unchanged.

Can I compare code with this diff checker?

Yes. The diff checker works with any plain text including source code, JSON, SQL, HTML, and prose.

Is my text stored anywhere?

No. All comparison happens entirely in your browser. Your text is never sent to a server.

What algorithm does this diff checker use?

It uses a line-by-line diff algorithm similar to the Unix diff utility.

Free Online Diff Checker

Compare two blocks of text and see exactly what changed — line by line or character by character — with additions and deletions highlighted. Runs fully in your browser.

Original Text

Changed Text

Ignore whitespace Ignore case

Frequently Asked Questions

What is a diff checker?: A diff checker compares two pieces of text and highlights the differences between them, showing what was added, removed, or changed.
What does the diff output mean?: Green lines were added in the new version. Red lines were removed from the original. White lines are unchanged.
Can I compare code with this diff checker?: Yes. The diff checker works with any plain text including source code, JSON, SQL, HTML, and prose.
Is my text stored anywhere?: No. All comparison happens entirely in your browser. Your text is never sent to a server.
What algorithm does this diff checker use?: It uses a line-by-line diff algorithm similar to the Unix diff utility.