Diff Checker
Compare two text blocks side by side and highlight the differences.
Diff Output
Frequently Asked Questions
What is the difference between line, word, and character mode?
The tool tokenizes your text differently before diffing. Line mode compares newline-separated lines, word mode compares tokens while preserving whitespace boundaries, and character mode compares one character at a time.
Why does a moved line show up as a removal and an addition?
The diff is based on a longest-common-subsequence comparison, not move detection. So a moved block is represented as delete-plus-add instead of a special "moved" state.
Is this a side-by-side visual diff like GitHub?
Not exactly. You enter original and modified text in two panes, but the result is rendered as one combined diff output with added, removed, and unchanged segments.
Does it run automatically while I type?
Yes. Input changes trigger a debounced compare after about 500 ms, and you can also force it immediately with the Compare button.
Why is the output area hidden when the texts are identical?
When there are no additions or removals, the tool shows a green "No differences" status instead and hides the detailed diff block. That is normal behavior, not a failed comparison.