Diff Checker
Compare two text blocks line by line. Added lines in green, removed in red.
Deep Dive
Perform a line-by-line comparison of two text blocks to highlight additions, deletions, and unchanged lines — similar to `git diff`. Ideal for comparing configuration files, code versions, or any two pieces of text. All comparison runs locally in the browser.
Who uses this?
- Reviewing changes to a configuration file before deploying
- Comparing two versions of a contract or document
- Verifying that a code refactor did not change behaviour
- Checking what changed between two API responses
Common Errors & Fixes
Entire file shows as changed when only one line differs
Check for mismatched line endings (CRLF vs. LF). Enable 'Ignore line endings' mode or normalize them first.
Diff is very slow for large files
The algorithm is O(n²) in the worst case. For files larger than a few thousand lines, use a desktop tool like VS Code or `diff`.
Colors are hard to read
Switch between light and dark mode. You can also switch to unified view for better contrast on small screens.
Expert FAQ
Does it compare character-level differences?
By default the tool diffs line by line. Within a changed line, it may highlight the specific words or characters that changed depending on the view mode.
Can I compare files instead of pasting text?
Yes. Use the file upload option to load text files directly. Binary files are not supported.
Does whitespace matter in the comparison?
By default, trailing whitespace differences are flagged. Enable 'Ignore whitespace' mode to suppress whitespace-only changes.