What is a Text Diff Checker?
A text diff checker (or "difference checker") is a tool that compares two versions of text and highlights what changed between them. It's invaluable for writers, editors, developers, and anyone who needs to track changes in documents.
How to Use This Text Diff Tool
- Paste your texts: Add the original version in the left box and the modified version in the right box
- Choose comparison mode: Select word-level (default), character-level, or line-level comparison
- Configure options: Toggle whitespace ignoring, case sensitivity, and line numbers as needed
- View differences: Switch between side-by-side or inline view to see changes
- Review statistics: Check additions, deletions, changes, and overall similarity percentage
- Export results: Copy the diff report for documentation or sharing
Understanding Diff Colors
- Green background: Text that was added in the modified version
- Red background: Text that was removed from the original
- Normal text: Unchanged content that appears in both versions
Common Use Cases
Content Revision Tracking
Compare draft versions of articles, blog posts, or marketing copy to see exactly what changed between revisions. Essential for editorial workflows and content approval processes.
Plagiarism Detection
Check if content has been copied or slightly modified. The similarity percentage helps quickly identify how much two texts have in common.
Document Version Comparison
Review changes in contracts, policies, or legal documents. Line-level diff is particularly useful for formal documents where every change matters.
Translation Quality Check
Compare original and edited translations to ensure accuracy and consistency. Track changes made by different translators or editors.
Code Review
While developers have Git, this tool works great for quick text-based code snippet comparisons without version control setup.
SEO Content Optimization
Compare before/after versions of optimized content to document SEO improvements and track keyword additions or removals.
Comparison Modes
Choose the right comparison mode based on what you're analyzing:
Word-Level Diff (Recommended)
Compares text word by word. This is the most commonly used mode as it balances detail with readability. Best for prose, articles, and general content.
Character-Level Diff
Shows changes at the character level. More granular than word-level, useful for finding small typos, punctuation changes, or precise edits within words.
Line-Level Diff
Compares entire lines. Best for structured content, lists, or code where changes typically happen at the line level. Easier to read for large blocks of text.
Understanding the Settings
Ignore Whitespace — When enabled, the diff checker treats multiple spaces, tabs, and line breaks as equivalent. Useful when formatting changes don't matter and you only want to see content changes.
Ignore Case — Makes the comparison case-insensitive. "Hello" and "hello" will be treated as identical. Helpful when checking content where capitalization varies but meaning is the same.
What the Statistics Mean
Additions
Count of words/characters/lines that were added in the modified version. High addition count indicates significant new content.
Deletions
Count of words/characters/lines removed from the original. High deletion count suggests major cuts or rewrites.
Total Changes
Combined number of additions and deletions. Represents the overall edit volume between the two versions.
Similarity
Measures how similar the two texts are, from 0% (completely different) to 100% (identical). Calculated based on matching content versus total content.
Tips for Effective Diff Checking
- Start with word-level: It provides the best balance of detail and readability for most content
- Use side-by-side for large changes: Easier to see context when texts are very different
- Use inline for minor edits: Better for reviewing small changes in similar texts
- Enable ignore whitespace: When you only care about content, not formatting
- Check similarity first: If similarity is very low (<30%), the texts might be too different for meaningful comparison
- Copy the report: Save diff results for documentation, change logs, or approval workflows
Privacy and Security
All text comparison happens entirely in your browser using JavaScript. Your content is never uploaded to our servers or stored anywhere. This tool is completely client-side for maximum privacy.
Related Tools
After comparing your texts, you might find these tools helpful:
- 📊 Word Counter - Count words and characters in your final text
- ⏱️ Reading Time Calculator - Estimate how long your revised content takes to read
- 📊 N-grams Analyzer - Check for repeated phrases in your edited text
