Diff Checker
Compare two files or texts online free — no paywall, no signup. Highlights additions, deletions, and changes line by line. Works for code, configs, documents.
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How to Use Diff Checker
- Paste your original text in the left panel
- Paste the modified text in the right panel
- Click "Compare" to see the differences
- Green highlights show additions (new content)
- Red highlights show deletions (removed content)
- Yellow/orange shows modified lines with character-level changes
About Diff Checker
Compare two pieces of text and instantly see what changed with our free Diff Checker. Whether you're reviewing code changes, comparing document versions, or debugging configuration differences, this tool highlights additions, deletions, and modifications clearly.
Diff Checker Features: - Side-by-Side View: Compare texts in parallel panels - Inline View: See differences in a unified format - Line-by-Line: Highlight changed lines - Character-Level: See exactly which characters changed - Color-Coded: Green for additions, red for deletions - Line Numbers: Easy reference for discussing changes
Comparison Modes: - Added Lines: New content (highlighted in green) - Removed Lines: Deleted content (highlighted in red) - Modified Lines: Changed lines with character-level diff - Unchanged Lines: Context around changes
Common Use Cases: - Code Review: Compare before/after code changes - Configuration Diff: Find differences in config files - Document Comparison: Track changes in text documents - Debug Changes: Identify what changed between versions - Contract Review: Spot differences in legal documents
Technical Details: Our diff algorithm uses the Myers diff algorithm, the same algorithm used by Git and other version control systems. It finds the minimal set of changes needed to transform one text into another.
All comparison happens in your browser—your texts are never uploaded, making it safe for comparing sensitive code or documents.
Common Use Cases
Frequently Asked Questions
How accurate is the diff detection?
We use the same Myers diff algorithm used by Git, which finds the minimum edit distance between two texts. It's highly accurate and efficient, handling large texts with thousands of lines.
What's the difference between inline and side-by-side view?
Side-by-side shows original and modified texts in parallel panels. Inline (unified) view shows everything in one panel with +/- prefixes, similar to git diff output. Choose based on your preference.
Can I compare files directly?
You can drag and drop text files onto the input areas, or copy file contents and paste them. The tool compares the text content, not the files themselves.
Does it ignore whitespace changes?
By default, all changes including whitespace are shown. This is important for code where whitespace matters. Some diff tools offer options to ignore whitespace for document comparison.
Is there a size limit for comparison?
The tool handles large texts well, but extremely large files (multiple megabytes) may cause browser slowdowns. For very large files, consider using command-line tools like diff or specialized software.
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