Text Diff: Compare Two Texts and Highlight Differences

Whether you’re comparing document revisions, checking code changes, or verifying content updates, a text diff tool shows you exactly what changed between two versions. Instead of reading both texts line by line, the diff highlights additions and removals instantly.

How Text Diff Works

Our tool uses a Longest Common Subsequence (LCS) algorithm to compare texts line by line. It identifies three types of changes:

• Added lines (green) — lines present in the modified text but not the original
• Removed lines (red) — lines present in the original but not the modified text
• Unchanged lines (gray) — lines identical in both versions, shown for context

Common Use Cases

Document Revisions

Compare drafts to see what an editor changed. Paste the original draft on the left and the revised version on the right to see every edit highlighted.

Content Updates

Check what changed between two versions of a web page, email template, or marketing copy. This catches unintended changes that might slip through manual review.

Configuration Files

Compare two versions of a config file to see what settings changed. This is especially useful when debugging issues after a deployment.

Data Verification

Compare exported data or API responses to verify they match expected values. Paste the expected output on one side and the actual output on the other.

Contract/Legal Documents

When receiving a revised contract, paste both versions to see every change the other party made. No change goes unnoticed.

How to Use Our Text Diff Tool

1. Paste the original text in the left panel
2. Paste the modified text in the right panel
3. Click Compare to see the differences
4. Review color-coded output: red for removals, green for additions

Options

• Ignore case — treat “Hello” and “hello” as the same
• Trim whitespace — ignore leading/trailing spaces when comparing

Tips

• The comparison is line-based — each line is treated as a unit
• If texts are identical, the tool tells you explicitly
• The stats badge shows the total count of added and removed lines
• Use “Ignore case” when comparing text where capitalization doesn’t matter

Understanding the Output

The diff output uses a familiar format:

- This line was removed from the original
+ This line was added in the modified version
  This line is unchanged (shown for context)

Lines are compared in sequence, so the diff maintains the flow of the document and shows changes in context.

Frequently Asked Questions

What if I swap the left and right panels? Additions become removals and vice versa. The comparison is directional — left is “before” and right is “after.”

Can it compare more than two texts? Our tool compares exactly two texts. For three-way merges, you’d need a specialized merge tool.

Does it work with code? Yes, but for code-specific diffs with syntax highlighting, consider using git diff or a dedicated code review tool. Our text diff works well for plain text and configuration files.

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Try our free Text Diff tool to compare texts and spot changes instantly.