Developer Utility

Text Diff Checker

Compare two texts to check added, removed, and unchanged lines. Useful for reviewing differences in sentences, code, configuration files, and notices before and after edits.

Line-based comparison Compare original and changed text line by line to find differences.
Change classification Separate added, removed, and unchanged lines to understand the edit flow.
Copy and download Copy comparison results or save them as a report file for sharing.

Text input

Enter the original text and changed text to compare.

Line-based comparison Useful for checking line-level changes in sentences, code, and configuration files.
Compare options Ignore spaces, blank lines, or case differences to focus on actual content changes.
Original 0 lines Changed 0 lines Change rate 0% Waiting to compare

Comparison result

Check added, removed, and unchanged lines with colors and symbols.

Ready
0 Added
0 Removed
0 Same
0 Total
Enter two texts and click the compare button.

How text comparison works

Results are classified line by line, making it easy to review document edits or code changes.

Added lines

Lines newly added in the changed text. Useful for checking new sentences, code, or settings.

Removed lines

Lines that existed in the original text but disappeared from the changed text.

Unchanged lines

Lines that exist identically in both texts, helping you see what stayed the same.

Help

What is Text Diff Checker?

Text Diff Checker is a free developer utility that compares two texts line by line and shows which lines were added, removed, or left unchanged.

Use it for comparing sentence edits, code changes, configuration files, blog drafts, and notice revisions.

Features

  • Compare two texts line by line
  • Classify added, removed, and unchanged lines
  • Options to ignore spaces, blank lines, and case
  • Show summary counts and change rate
  • Trim leading and trailing spaces
  • Load sample text
  • Copy results and download a report

Use cases

  • Check sentence changes before and after editing
  • Compare code snippet changes
  • Compare blog drafts with revised versions
  • Check configuration file changes
  • Review wording differences in terms, guides, and notices
  • Find missing lines in copied text
How are text comparison results displayed?

Newly added lines are marked with +, removed lines with -, and unchanged lines with =. The summary also shows added, removed, unchanged, and total line counts.

When should I ignore leading and trailing spaces?

Use this when lines only differ by spaces at the beginning or end, but the actual content is the same.

When is excluding blank lines useful?

Use this when you want to exclude empty lines created by document spacing or copy-paste gaps.

What does ignore case mean?

This option treats uppercase and lowercase English letters as the same. For example, Hello and hello can be considered identical.

Can it compare by word?

This tool is based on line-level comparison. If only one word changes in a sentence, the whole line may still appear in the change flow.

Can I enter sensitive text?

This tool compares text in the browser, but it is still recommended to remove or mask passwords, API keys, personal information, and internal documents before entering them.