Text Diff

Compare two texts side-by-side with instant visual diff. Character, word, and line-level comparison with color-coded additions, deletions, and changes. 100% client-side — nothing leaves your browser.

Diff:
View:
Original
Modified
Added: 0
Removed: 0
Changed: 0
Similarity:
Original
Modified
Unified Diff
Paste or type text to compare
Press Ctrl+Enter to compare

What is a text diff tool?

A diff tool finds and displays the differences between two pieces of text. It's essential for developers, writers, and anyone who needs to track changes.

01

Paste your texts

Put the original text in the left panel and the modified version in the right panel. You can also drag and drop files directly, or use the Load File button.

02

Choose comparison mode

Select character-level for granular typo detection, word-level for prose editing, or line-level (default) for code review and structured documents.

03

Read the color-coded diff

Green highlights show additions, red shows deletions, and yellow marks modified lines. Inline highlights within changed lines show exactly what words or characters changed.

04

Export your results

Copy the diff to your clipboard or download it as a .diff file compatible with standard patch tools like git apply. Use the stats bar to check similarity percentage.

Use cases for developers & writers

Text diff tools are used daily by millions of developers and content creators. Here's how.

💻

Code review

Compare two versions of a source file to review changes before committing. Line-level diff mode with side-by-side view mimics the Git diff experience right in your browser.

📝

Document revision tracking

Compare draft versions of articles, contracts, or policies. Word-level diff highlights rewritten sentences so editors can approve or reject specific changes.

🔎

Configuration file auditing

Spot unintended changes in .env files, nginx configs, or YAML deployments. The ignore-whitespace toggle prevents false positives from formatting differences.

🔧

API response debugging

Paste two JSON or XML API responses side-by-side to find exactly which fields changed. Character-level diff catches even single-character differences in values.

📚

Translation comparison

Compare translated text with the original to ensure nothing was accidentally omitted or duplicated during the translation process.

🚀

Deployment verification

Download the .diff output file and use it with patch tools to apply changes systematically. Standard unified diff format works with git apply and GNU patch.

Frequently asked questions

What is a text diff tool?

A text diff tool compares two pieces of text and highlights the differences between them. It shows what was added, removed, or changed. This tool uses the Myers diff algorithm — the same algorithm behind Git's diff command — to find the minimum set of changes needed to transform one text into the other.

What's the difference between character, word, and line-level diff?

Character-level compares every individual character — best for finding typos or single-character edits. Word-level compares whole words, making it easier to read when sentences have been rewritten. Line-level compares entire lines, which is the standard for code review and the fastest option for large files.

Is my text data private and secure?

Yes. This tool runs entirely in your browser using JavaScript. Your text is never sent to any server, never stored, and never logged. You can disconnect from the internet and it still works. The diff computation happens 100% on your machine.

What does the Myers diff algorithm do?

The Myers diff algorithm (published by Eugene W. Myers in 1986) finds the shortest edit script — the minimum number of insertions and deletions needed to transform one sequence into another. It runs in O(ND) time where N is the total length and D is the edit distance. It's the same algorithm used by Git, GNU diff, and most modern version control systems.

Can I compare code files with this tool?

Yes. Drag and drop source code files directly into the input panels, or use the Load File button. Supports .js, .py, .html, .css, .json, .xml, .sql, .java, .c, .cpp, .go, .rs, .ts, .yaml, and many more. The .diff download is compatible with git apply and GNU patch.

What do "Ignore Whitespace" and "Ignore Case" do?

"Ignore Whitespace" normalizes all whitespace (spaces, tabs, multiple spaces) to single spaces and trims line endings before comparing. This prevents trivial formatting differences from showing up as changes. "Ignore Case" converts both texts to lowercase before comparing, useful when case changes aren't meaningful.

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