How to Use the Diff Checker

Paste the original version of your text into the left panel.
Paste the modified version into the right panel.
Click Compare to see the differences.
Green lines were added, red lines were removed, and unchanged lines are shown without color.

Common Uses

Compare two versions of a document, essay, or article to find edits.
Check what changed between two code snippets without using Git.
Verify that two configuration files are identical or spot the difference.
Review changes made by collaborators in shared documents.
Compare API responses to find what changed between two calls.

Frequently Asked Questions

How does the diff algorithm work?

This tool uses the Myers diff algorithm — the same algorithm used by Git. It finds the longest common subsequence of lines between the two texts and marks everything else as added or removed.

Is there a size limit?

No hard limit. The diff runs in your browser. Very large texts (thousands of lines) may take a second to process but will complete without errors.

Does it compare word-by-word or line-by-line?

Line-by-line. If a single word changes within a line, the whole line is marked as removed and the new version is marked as added. This matches how Git shows diffs.

Is my text sent to a server?

No. All comparison happens locally in your browser. Your text never leaves your device.

Diff Checker