Text Diff Checker
A diff checker compares two texts to find differences. It highlights additions (green), deletions (red), and modifications (yellow). View modes include side-by-side (parallel columns) and inline (unified diff with +/- markers). Supports both line-level and character-level comparison.
Compare two texts and highlight differences. Side-by-side or inline view with line numbers. Supports character-level and line-level diff comparison.
Original Text
Modified Text
How to Use
- Side by Side: View original and modified text in parallel columns
- Inline: View changes in a unified diff format with +/- markers
- Line Level: Compare entire lines (faster for large texts)
- Character Level: Highlight individual character changes within lines
- Swap: Switch the original and modified texts
- Ignore Whitespace: Treat whitespace differences as equal
- Ignore Case: Compare text case-insensitively
- Sample: Load example texts to see the tool in action
Ctrl/⌘ + Enter to compare • Esc to reset
How to Use
- 1
Paste original text
Enter or paste the original text in the left/first text area
- 2
Paste modified text
Enter or paste the modified text in the right/second text area
- 3
Choose view mode
Select side-by-side for parallel comparison or inline for unified diff
- 4
Select diff level
Choose line-level for faster comparison or character-level for detailed changes
- 5
Compare texts
Click Compare to see the differences highlighted with colors and line numbers
- 6
Copy diff output
Click the copy button to copy the diff in unified format (+/- notation)
Frequently Asked Questions
- What is a diff checker?
- A diff checker is a tool that compares two texts and highlights the differences between them. It shows additions (new content), deletions (removed content), and modifications. Diff tools are commonly used in programming, document editing, and version control.
- What is the difference between side-by-side and inline diff?
- Side-by-side diff shows original and modified text in parallel columns, making it easy to compare corresponding lines. Inline diff (unified diff) shows changes in a single column with + for additions and - for deletions. Side-by-side is better for visual comparison, while inline is more compact.
- What is character-level vs line-level diff?
- Line-level diff compares entire lines and marks whole lines as added, removed, or modified. Character-level diff goes deeper, highlighting the specific characters that changed within a line. Character-level is more precise but slower for large texts.
- How does the LCS algorithm work for diff?
- LCS (Longest Common Subsequence) finds the longest sequence of elements common to both texts. Elements not in the LCS are either additions or deletions. This algorithm ensures the diff shows minimal changes needed to transform one text into another.
- What do the colors mean in a diff output?
- Green indicates additions (new content in modified text). Red indicates deletions (content removed from original). Yellow indicates modifications (lines that changed). Unchanged lines have no highlighting. This color scheme is standard in most diff tools.
- Can I use this diff checker for code?
- Yes, this diff checker works great for comparing code files, configuration files, JSON, or any plain text. It preserves whitespace and shows line numbers, making it suitable for code review and debugging. For syntax highlighting, use a dedicated code diff tool.