Diff Checker
Text Diff Checker Online – Compare Texts Side-by-Side
About Diff Checker
A Diff Checker highlights visual differences between two blocks of text. It is ideal for code reviews, manuscript editing, and checking config versions.
How It Works
Offloaded to a background Web Worker, the diff engine runs a Myers-style longest-common-subsequence algorithm with linear space refinement.
How to Use Diff Checker
- Paste your original text in the left pane, and the modified version in the right pane.
- Toggle split (side-by-side) or unified (inline) view mode.
- Optionally enable options to ignore whitespace discrepancies or character casing.
- Review the highlighted red/green additions and deletions.
FAQ
How big can the inputs be?
Anything that fits in memory. The diff core uses a Myers-style longest-common-subsequence algorithm with linear-space refinement, which handles multi-megabyte inputs comfortably.
Under the hood
Inputs are tokenised by newline (or by character for character mode), passed through a Myers diff implementation, then folded back into aligned rows for rendering. Hunks are virtualised so the DOM stays small even for massive diffs.
Engineered by HaorGrix