Text Diff Guide: Compare Texts and Find Differences Like a Developer
Learn how text diff checkers work, common use cases for comparing code and documents, and how to interpret diff output for debugging and code review.
What Is a Text Diff?
A text diff (difference) is the result of comparing two sequences of text to find the changes between them. Diff algorithms identify additions, deletions, and modifications at the line and character level. The most common algorithm is the Myers diff algorithm, used by Git and most diff tools.
Common Diff Use Cases for Developers
Code reviews — compare pull request changes before merging. Debugging — compare working code with broken code to isolate the issue. Configuration management — track changes in config files across environments. Version comparison — see what changed between software versions. Document revision tracking — find edits in text documents.
How to Read Diff Output
Diff output typically shows two panes side by side or a single unified view. Additions are shown in green (new lines), deletions in red (removed lines), and unchanged lines in gray. Some tools highlight character-level changes within lines for precise comparison.
Diff in Version Control
Git uses diff extensively — git diff shows unstaged changes, git diff --staged shows staged changes, and git log -p shows the patch for each commit. Understanding diff output is essential for effective Git usage and collaborative development.
Using the WebUtil Text Diff Checker
Our free Text Diff Checker compares two texts side-by-side and highlights additions, deletions, and changes. Paste your original and modified text, and see the differences highlighted instantly. Perfect for code reviews, document comparison, and debugging. All processing runs client-side.
Use our free online tool to get started instantly.