What is Text Diff Checker?

Text Diff Checker compares original and revised text side by side, then highlights what was added, removed, and changed. The diff updates in real time as you type, down to the exact words that changed inside a line. The result can also be copied as a unified diff, ready to paste into review comments or tickets.

Everything runs in the browser, so you can review the content locally while comparing it.

How to Use

1. Enter or paste the original and revised text. Line and character counts are shown under each field.
2. The diff appears immediately and updates as your input changes.
3. Use the Swap button when you want to exchange the original and revised text.
4. In long text, use the previous and next change buttons to move between diff blocks. Alt+↑ and Alt+↓ also jump between them.
5. Adjust the options to tune the diff view for the text you are reviewing.

Main Settings

Comparison Options

• Ignore whitespace: treats whitespace differences inside a line as equal. Useful when you want to filter out indent-only changes and focus on the content.
• Ignore case: treats letter-case differences as equal. Useful for checking spelling variations.

Display Options

• Highlight: switches how finely changed lines are emphasized, by lines or characters. With characters, the exact words that changed inside a line are shown.
• No height limit: removes the height limit of the result area so every line shows with the page scroll.
• Wrap lines: wraps long lines instead of scrolling horizontally.

Use Cases

• Checking the scope of function, style, or markup edits before opening a pull request
• Reviewing rewrites in articles, meeting notes, or proposal drafts to see what wording changed
• Comparing JSON, YAML, or other settings where a small text change can affect behavior
• Sharing changes in the unified diff format