Text Diff Checker (Diff)
Compare two texts side-by-side and highlight additions, deletions, and modifications.
Processes securely within your browser, ensuring confidential documents remain safe.
Simply paste the two texts you want to compare into the input fields and click "Compare Diff". Added, deleted, and modified parts will be highlighted in different colors.
Your input data is never sent to a server. All processing is completed securely within your browser.
📝 📝 Text Input
⚙️ ⚙️ Comparison Options
📊 📊 Diff Result
About the Text Diff Checker
This is an online tool that compares two texts side-by-side and highlights the differences (additions, deletions, modifications). It supports character-level and line-level diff detection, allowing you to visually confirm changes.
It is highly useful for code reviews, verifying document modifications, and comparing configuration files. It also supports options like ignoring whitespaces and case differences.
All processing is done entirely within your browser, and your data is never sent to a server. No registration is required, and you can start using it immediately.
How to Use
Enter texts to compare
Paste the texts you want to compare into the left and right input fields respectively.
Configure options and compare
Set options like ignore whitespace or case as needed, then run the comparison.
Check the diff results
Additions are highlighted in green, and deletions in red. You can see the exact changes at a glance.
Text Diff Glossary
- diff
- Extracting differences by comparing two texts or files. Originated from the Unix diff command.
- LCS (Longest Common Subsequence)
- The algorithm underlying diff detection. It finds the longest sequence of characters common to both texts.
- Inline View
- A style where added and deleted lines are listed vertically. It is easy to follow the overall flow by scrolling vertically, making it ideal for mobile devices.
- Side-by-side View
- A style where old and new texts are placed side by side. Adopted by platforms like GitHub, it intuitively shows the relationship before and after changes.
- Added Line
- A line that does not exist in the old text but is added in the new one. Generally indicated by a "+" sign and green highlight.
- Deleted Line
- A line that exists in the old text but is deleted in the new one. Generally indicated by a "-" sign and red highlight.
- Character-level Diff
- Detailed diff detection to identify minor changes within a line (e.g., typo fixes). Only the changed characters are highlighted in a darker color.
- Normalization
- A process performed before comparison to ignore format differences, such as removing whitespaces or unifying text case, to reduce noise.
FAQ
- Q.Can I compare large files?
- Yes, it depends on your browser memory, but it can handle tens of thousands of lines without issue.
- Q.Does it support syntax highlighting for programming languages?
- No, it specializes in text-based diff comparison and does not feature code syntax highlighting.
- Q.Is my data sent to a server?
- No. All processing is done entirely in your browser using JavaScript. No data is sent to any server.
- Q.Can I use it on smartphones and tablets?
- Yes. It is responsive, and the inline view mode is especially optimized for mobile devices.
- Q.Can I compare PDF or Word files?
- This tool is for plain text only. Please copy and paste the text from your files into the tool.
- Q.What does "Ignore whitespace differences" do?
- It ignores differences in spaces and tabs, comparing only the text content. This helps reduce noise from indentation changes.
- Q.Can I export the diff result?
- Currently, there is no export feature. You can view the results on the screen or copy the modified text for your use.
- Q.Why is everything highlighted in red and green?
- This might be due to differences in line endings (CRLF vs LF) or whitespaces. Try checking the "Ignore whitespace differences" option.
Use Cases
Code Review
Check diffs before making a pull request. Accurately grasp the changes to improve review efficiency.
Document Modification Check
Compare revisions in contracts, specifications, or terms of service. Ensure no minor word changes are overlooked.
Config File Comparison
Detect differences between production and development config files. Useful for checking environment variations before deployment.
Data Validation & Log Analysis
Find changes in data files like CSV or JSON, or investigate diffs in error logs output by the system.
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Please let us know your thoughts to help us improve the tool.
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