About This Tool
Text Diff finds lines retained in both versions instead of comparing only matching line numbers. Inserting a line in the middle does not incorrectly mark every later line as changed. Colors, symbols, and line numbers explain the result together.
How to Use It
- Enter the original text on the left and the revised text on the right.
- Click Compare. Large text is not compared again on every keystroke.
- Review green additions, red deletions, and unchanged lines, with symbols and old/new line numbers.
- Copy or download the diff as TXT. Reduce the comparison scope if the input exceeds the processing budget.
Examples
- Compare A / B / C with A / X / B / C: only X is added; B and C remain unchanged.
- A deleted line has a “-” marker and an added line has “+”. A replacement can appear as a deletion followed by an addition.
- Text containing <script> is displayed literally and never executed.
Rules and Limits
Text is compared by whole lines, with line endings normalized to LF. The two inputs can total up to 1 MiB, with up to 10,000 lines on each side. Extensive differences may reach the processing limit; compare chapters or smaller sections if prompted. The preview shows the first 2,000 differences, while copying and downloading include the complete calculated result.
Common Uses
- Review changes to settings, documentation, or logs.
- Locate inserted and deleted list entries.
- Compare versions containing Chinese, Japanese, emoji, or other Unicode text.
Privacy
Your text, files, and previews are processed in your browser. Your input is never uploaded or automatically saved. Save anything you need to keep before leaving the page.
FAQ
What do Added and Removed mean?
Added marks a line introduced in the revised text. Removed marks a line deleted from the original. Matching content is unchanged.
Why not just compare the same line numbers?
Insertions and deletions shift later line numbers without necessarily changing those lines. The tool recognizes retained content so it does not mark the entire following passage as changed.
Can I compare empty text?
Yes. If one side is empty, the other side’s lines are additions or deletions. If both sides are empty, there is no difference.
Can I compare files of any size?
No. Input size, line count, and the amount of change are limited to keep the page responsive. If you reach a limit, compare a smaller section as prompted.
Is the text uploaded or executed?
No. Comparison happens in your browser without uploading or executing your text. Even script tags are displayed as ordinary text.