Text Diff Checker
Compare two text snippets and see the differences highlighted line by line.
The quick brown fox jumps over the lazy dog.The quick red fox jumps over the lazy cat.
About Text Diff Checker
Paste two versions of any text or code snippet side by side and instantly see insertions (green), deletions (red), and unchanged lines. Useful for comparing config files, reviewing code changes without Git, checking document revisions, or verifying two API responses differ only where expected.
All processing happens entirely in your browser using modern web APIs. Nothing is uploaded to our servers — your data stays local and private. Free to use forever.
Common use cases
- Comparing two versions of a config file to find unexpected changes
- Reviewing text edits without needing a code editor or Git
- Checking whether two JSON/XML/YAML responses are equivalent
- Verifying a migration script before and after transformation
- Comparing documentation versions to find what changed
How it works
Uses the diff library's diffLines() algorithm which performs a Myers diff on the line-level tokens of both inputs. The algorithm finds the longest common subsequence and marks remaining lines as additions or removals. Added lines are shown in green with a + prefix, removed lines in red with a - prefix, and context lines in gray.