How do I compare code online for free?
Simply paste your original code in the left panel and your modified code in the right panel. Click 'Compare Now' to instantly see all additions (green) and deletions (red) highlighted.
📂 Code Comparison
Diff Checker
Professional diff tool with line numbers, syntax gutter, and file upload. Supports line-by-line, word-by-word, and character-level comparison.
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Why use an Online Code Compare Tool?
A code compare tool is essential for developers to identify logic changes, debug regressions, and perform quick audits between file versions.
| Feature | Line Diff | Word Diff | Char Diff |
|---|---|---|---|
| Best For | Programming Code | Articles / Text | API Keys / Hashes |
| Accuracy | High (per line) | High (per word) | Exact Logic |
| Speed | Fastest | Balanced | Granular |
Types of Comparison
- Line-by-Line: Best for source code and structured data where each change usually happens on a new line.
- Word-by-Word: Ideal for articles, blog posts, and long-form writing to see exactly which words were edited.
- Character-Level: Use this for very precise comparisons, such as finding a single mismatched character in a hash or API key.
Privacy Guaranteed
Binary comparison logic happens entirely in your browser using the fast-myers-diff (MIT) library. Your sensitive code or text snippets are never sent to any server for processing.
Frequently Asked Questions
Is my code secure when using this comparison tool?
Yes. All code comparison happens 100% in your browser using client-side JavaScript. Your source code is never uploaded to any server.
What types of code comparison are supported?
We support three modes: Line-by-line (best for source code), Word-by-word (best for articles and text), and Character-level (best for finding tiny differences in hashes or API keys).
Can I upload files to compare?
Yes! Each editor panel has a 'Load File' button that accepts .js, .py, .java, .html, .css, .json, .xml, .md, and many more file types. You can also drag and drop files directly onto each editor.
What keyboard shortcuts are supported?
Press Ctrl+Enter (Cmd+Enter on Mac) to instantly run the comparison. This allows a fast edit-compare workflow without clicking buttons.
What does 'Ignore whitespace' do?
When enabled, the comparison treats lines that differ only in spaces, tabs, or trailing whitespace as identical. This is useful when comparing code that has been reformatted.
What do the colors mean in the diff output?
Green highlights text that was added in the modified version. Red highlights text that was removed from the original version. Unchanged text is shown normally.