How to compare two text files online?

Paste your text into the left and right panels, or click 'Open file…' to upload files. The diff is computed instantly and highlights added lines in cyan and removed lines in red.

Is this the best diff tool for Python code?

Compare Text File supports Python (.py) files with syntax-aware comparison. Upload two Python files and see line-by-line differences instantly, with word-level highlighting for small changes.

Can I compare JSON files for free?

Yes. Upload or paste two JSON files and Compare Text File will show you exactly which keys and values differ. It's completely free and your data never leaves your browser.

Does this tool work offline?

After the initial page load, Compare Text File works fully offline. All diff computation runs in your browser — no internet connection is required.

Is my data safe when using this tool?

Yes. All text processing happens entirely in your browser. Your files and text are never sent to any server, stored, or shared with anyone.

Compare Any Two Text or Code Files Instantly

The fastest free online text file comparison tool. Use our online text file comparison tool to compare two files side-by-side in seconds — paste text or upload files directly. Supports Python, JavaScript, JSON, HTML, CSV, and 50+ more languages. Your data never leaves your browser.

Why Use Compare Text File?

⚡ Real-Time Diff

Results appear as you type — no button to click. Diffs update within 500ms.

🔒 100% Private

All processing runs in your browser. Nothing is uploaded to any server.

🌐 50+ Languages

Auto-detects Hindi, Arabic, Chinese, Japanese, and more. Full RTL support.

📂 Drag & Drop

Upload files by dragging them onto the panel. Supports .txt, .py, .js, .json, .html, .csv and more.

🔤 Word-Level Diff

Highlights individual changed words within lines, not just whole lines.

📤 Export Diff

Copy the diff to clipboard or download as a standard .diff file compatible with git.

How It Works

Upload or paste — Paste text directly or drag & drop / upload your files into the left and right panels.
Compare instantly — The diff is computed in real time. Added lines are highlighted in cyan, removed lines in red.
Download or copy — Export the diff as a .diff file or copy it to your clipboard with one click.

Supported File Types & Languages

Compare Text File works with any plain-text format:

Python (.py) JavaScript (.js) TypeScript (.ts) JSON (.json) HTML (.html) CSS (.css) CSV (.csv) Markdown (.md) Java (.java) SQL (.sql) YAML (.yml) XML (.xml) Plain Text (.txt) Shell (.sh) Go (.go) Rust (.rs) Ruby (.rb) PHP (.php) C/C++ (.c/.cpp) + 30 more

Frequently Asked Questions

How to compare two text files online?: Paste your text into the left and right panels, or click "Open file…" to upload files. The diff is computed instantly and highlights added lines in cyan and removed lines in red. No sign-up required.
What is the best diff tool for Python code?: Compare Text File supports Python (.py) files with line-by-line and word-level comparison. Upload two Python files and see differences instantly, with word-level highlighting for small changes within lines.
Can I compare JSON files for free?: Yes. Upload or paste two JSON files and Compare Text File shows exactly which keys and values differ. It's completely free and your data never leaves your browser.
How do I compare two files using drag and drop?: Drag any text file from your computer and drop it onto the left or right panel. A blue dashed border appears when you hover over the drop zone. The file loads instantly without any upload to a server.
Is this file difference checker free?: Yes, Compare Text File is completely free to use with no limits on file size (up to 5MB), no sign-up, and no ads blocking the tool.
Does this tool work offline?: After the initial page load, Compare Text File works fully offline. All diff computation runs in your browser — no internet connection is required.
Is my data safe when using this online diff tool?: Yes. All text processing happens entirely in your browser. Your files and text are never sent to any server, stored, or shared with anyone.
Can I compare files in Hindi, Arabic, or Chinese?: Yes. Compare Text File supports 50+ languages including Hindi, Arabic, Chinese, Japanese, Korean, and more. The language is auto-detected and the correct font is applied automatically. Arabic and Hebrew use right-to-left layout.
How do I download the diff output?: Click the "⬇ Download" button in the toolbar to save the diff as a standard diff-output.diff file. You can also click "📋 Copy" to copy the unified diff to your clipboard.
What is the maximum file size I can compare?: Each file can be up to 5MB in size. Binary files (images, executables, PDFs) are automatically rejected with a clear error message.

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