What is Diff Master?
Diff Master is a text and code comparison tool that highlights differences between two versions of content. It supports character-level, word-level, and line-level diff, with syntax highlighting for code files. Beyond simple text diff, it can compare structured data like JSON and XML semantically, ignoring formatting differences to show actual content changes.
Why Use This Tool?
Comparing text and code is essential for code review, debugging, and version control. Standard diff tools show line changes but miss context. Diff Master provides: semantic JSON diff that ignores formatting, side-by-side and inline views, syntax highlighting for 50+ languages, and the ability to merge changes. It's especially useful for comparing configuration files and API responses.
How to Use Diff Master
- Paste original text/code on the left side
- Paste modified version on the right side
- Differences are highlighted immediately
- Toggle between side-by-side and inline views
- For JSON/XML, enable semantic diff to ignore formatting
- Use merge controls to build a combined version
Features
- Line, word, and character-level diff highlighting
- Side-by-side and inline (unified) views
- Syntax highlighting for 50+ languages
- Semantic JSON diff (ignores whitespace, key order)
- XML diff with namespace awareness
- Merge editor to combine changes
- Ignore whitespace option
- Line numbers and navigation controls
Common Use Cases
- Code Review: Compare versions before and after changes
- Debugging: Find differences between working and broken versions
- Configuration: Compare config files across environments
- API Testing: Compare expected vs actual API responses
- Documentation: Track changes in text documents
Tips & Best Practices
- ✓ Use semantic diff for JSON/XML to focus on actual data changes
- ✓ Character-level diff helps find typos in similar strings
- ✓ Copy cURL responses directly for API comparison
- ✓ Enable "ignore whitespace" for code that was reformatted
How It Compares to Alternatives
Diffchecker.com is popular but uploads your data for server-side processing. Diff Master runs entirely in your browser, making it safe for sensitive code and config files. Unlike git diff, it provides a visual interface with merge capabilities.
Frequently Asked Questions
How do I compare two text files online?
Paste your original text on the left and modified text on the right. Differences are highlighted instantly with additions in green and deletions in red. Line-by-line and character-level diff available.
Can I compare JSON files?
Yes! Our diff tool understands JSON structure. It ignores formatting differences and shows semantic changes - modified values, added keys, removed properties - even if the JSON is reformatted.
How do I merge differences?
Click on any highlighted difference to accept or reject changes. Build your merged output by choosing which version of each change to keep.
Ready to Get Started?
Use Diff Master for free - no registration required.
Launch Diff Master