The Diff Match and Patch libraries offer robust algorithms to perform the operations required for synchronizing plain text.

1. Diff:
• Compare two blocks of plain text and efficiently return a list of differences.
• Diff Demo
2. Match:
• Given a search string, find its best fuzzy match in a block of plain text. Weighted for both accuracy and location.
• Match Demo
3. Patch:
• Apply a list of patches onto plain text. Use best-effort to apply patch even when the underlying text doesn't match.
• Patch Demo

Currently available in Java, JavaScript, C++ and Python. Regardless of language, each library features the same API and the same functionality. All versions also have comprehensive test harnesses.

Public Users

• Google Documents
• MobWrite
• Collabedit
• Your project here...

Algorithms

This library implements Myer's diff algorithm which is generally considered to be the best general-purpose diff. A layer of pre-diff speedups and post-diff cleanups surround the diff algorithm, improving both performance and output quality.

This library also implements a Bitap matching algorithm at the heart of a flexible matching and patching strategy.