Text Diff Checker
Guide: Regex Cheat Sheet for Beginners
Nothing you enter or choose here leaves your device. This tool runs in your browser.
How to use
- 1Paste the original text on the left and the changed text on the right.
- 2Read the summary of added and removed lines.
- 3Look at the side-by-side view. Red marks removed text and green marks added text.
- 4Use the options to ignore case or extra spaces, or show only the changes.
Frequently asked questions
How does the comparison work?
It compares the two texts line by line to find the longest set of lines they share, then highlights the individual words that differ inside changed lines.
Can I compare code?
Yes. The text is shown in a monospace font and line numbers are included, so it works well for code, config files and JSON.
What do "ignore case" and "ignore extra whitespace" do?
They treat "Hello World" and "hello world" as the same line, so only meaningful changes are highlighted.
Is my text uploaded anywhere?
No. The comparison runs entirely in your browser and nothing is sent to a server.
Read the guide
Learn how this works and how to get the most from it.
Developer
Regex Cheat Sheet for Beginners
A plain-English guide to regular expressions: character classes, quantifiers, groups, flags and examples you can test.
2 min read
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