BBuildQuill
Developer Tools

Diff Checker

Compare two texts and highlight added, removed, and unchanged lines instantly.

How to Use Diff Checker

1

Paste original text

Enter the original or older version of the text in the left panel.

2

Paste modified text

Enter the new or updated version in the right panel.

3

Read the diff

Green lines are additions, red lines are removals. Unchanged lines are shown in the middle.

What is the Diff Checker?

Compare two blocks of text side by side and instantly see what changed. Added, removed, and unchanged lines are highlighted with distinct colors, making it easy to review edits in code, documents, or configuration files.

  • Line-by-line comparison with color-coded highlights
  • Detects added, removed, and unchanged lines
  • LCS-based diff algorithm for accurate results
  • Real-time updates as you type in either panel
  • Works with code, prose, config files, and any plain text
  • Clear visual summary of total changes

Frequently Asked Questions

How does the diff algorithm work?
It uses the Longest Common Subsequence (LCS) algorithm to identify which lines are equal, added, or removed between the two texts.
Is this a line-by-line or character diff?
Line-by-line. Each line is compared as a whole unit. This is the most readable format for comparing code and documents.
Can I compare code files?
Yes. Paste any text including code, configuration files, or documents. The diff updates as you type.

Related Tools

JSON Formatter

Format, validate, and beautify JSON data with syntax highlighting.

Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 strings back to text.

URL Encoder/Decoder

Encode or decode URLs and query parameters for safe transmission.

HTML Entity Encoder

Encode special characters to HTML entities or decode them back.