Text Diff Checker
Compare two texts and highlight differences
Input & options
Your inputs are never uploaded or stored.
Results
Enter your values to see the result.
Free Online Text Diff Checker & Comparison Tool
Our text diff checker is a free online tool that compares two texts side by side and highlights every difference between them. Paste two versions of a config file, a contract clause before and after review, or an article before and after editing, and this text comparison tool identifies added, removed, and modified lines with clear color-coded highlighting.
The tool performs a line-by-line comparison and generates detailed statistics showing exactly how many lines were added, removed, or modified. Results are displayed in a familiar diff format with green for additions, red for removals, and yellow for modifications. You can copy the diff output, download a full comparison report, or swap the texts for a reverse comparison.
All text comparison is private: nothing you paste is uploaded or stored. This makes the tool safe for comparing confidential code, legal documents, and proprietary content. The diff checker works with text of any length and produces instant results.
Key Features
- Line-by-line text comparison with color-coded highlighting
- Statistics dashboard showing added, removed, and modified line counts
- Green, red, and yellow color coding for easy visual scanning
- Swap texts function for instant reverse comparison
- Copy diff results to clipboard in standard diff format
- Download full comparison report as a text file
- Line number display for precise reference to changes
- Real-time comparison that updates as you type or paste
- Scrollable diff output for comparing long documents
- Dark mode support for comfortable use in any lighting
How to Use the Text Diff Checker
- Paste the original text: Enter or paste your original text into the left text area labeled Original Text.
- Paste the modified text: Enter or paste the modified version of your text into the right text area labeled Modified Text.
- Review the differences: The tool instantly highlights all differences with color coding, showing added lines in green, removed lines in red, and modified lines in yellow.
- Check the statistics: Review the comparison statistics panel to see the total count of added, removed, and modified lines.
- Export the results: Use Copy Diff to copy the results to your clipboard or Download to save a full report as a text file.
- Swap if needed: Click Swap Texts to reverse the comparison direction and see the changes from the opposite perspective.
Use Cases
- Code reviews: Compare two versions of source code to identify exact changes before merging or deploying updates.
- Document versioning: Track changes between different drafts of contracts, reports, policies, or proposals.
- Content editing: Review edits made by collaborators by comparing original and revised versions of articles or blog posts.
- Configuration auditing: Compare configuration files, server settings, or environment variables to detect unintended changes.
- Plagiarism detection: Compare two texts to identify similarities and differences in academic or published content.
- Translation verification: Compare translated text against the original to ensure accuracy and completeness.
- Legal document review: Identify clause changes between contract revisions or policy updates.
Frequently Asked Questions
How does the comparison algorithm work?
The tool performs a line-by-line comparison of both texts. Lines present only in the modified text are marked as added, lines missing from the modified text are marked as removed, and lines that exist in both but differ are marked as modified.
Can I compare code files?
Yes. The diff checker works with any plain text content including source code in any programming language, configuration files, JSON, XML, and more.
Is there a size limit for text comparison?
There is no hard limit, so large documents work. Very large texts with thousands of lines may take a moment to compare, depending on your device.
Tips & Best Practices
- Normalize line endings first: Ensure both texts use the same line ending style (LF or CRLF) to avoid false differences caused by invisible characters.
- Use the statistics panel: The added, removed, and modified counts give you a quick summary before diving into line-by-line details.
- Download reports for records: Use the download feature to save comparison results for documentation, audits, or review records.
- Swap texts for perspective: Clicking Swap Texts lets you see the same changes from the opposite direction, which can be useful for understanding the impact of edits.
- Compare incrementally: For large documents, compare sections at a time to make the review process more manageable.
- Trim trailing whitespace: Remove trailing spaces from both texts before comparing to focus on meaningful content differences.