Instantly identify any file format by analyzing its binary signature and magic bytes. This free tool supports 500+ formats and works entirely in your browser for complete privacy. Perfect for security verification, data recovery, or web development.
Frequently Asked Questions
Simply drag and drop your file into the upload area or click to browse. The tool instantly analyzes the file's magic bytes and binary signature to identify its true format. Unlike other tools that only check the extension, we examine the actual file structure for accurate results.
It's a tool that identifies the true format of any file by analyzing its binary signature and magic bytes, rather than relying on the file extension. This method is more accurate because extensions can be easily changed, but the internal file structure cannot be faked.
The most accurate method is to examine the file's header and
magic bytes - unique signatures at the beginning of each file format. Our tool reads these signatures and matches them against a database of a lot known formats to determine the
MIME type, extension, and category.
Yes, completely safe. Nothing gets uploaded to any server - all analysis happens locally in your browser using WebAssembly technology. Your files never leave your device, ensuring complete privacy and security.
Our file detector supports 500+ file types including: documents (PDF, DOCX, XLSX), images (PNG, JPEG, GIF, WebP, SVG), videos (MP4, AVI, MOV), audio (MP3, FLAC, WAV), archives (ZIP, RAR, 7Z), executables, databases, and many more formats.
File extensions can be easily changed or removed, making them unreliable. Checking the actual binary signature reveals the true format, which is essential for security (detecting malware), data recovery, web development (correct MIME types), and verifying file authenticity.
How It Works
Instead of relying on file extensions (which can be easily changed), our tool analyzes the actual binary structure of your files. We examine the file header and magic bytes - unique signatures that identify the true format regardless of the extension. This method is far more reliable and can detect files with incorrect or missing extensions.
Key Features
- 500+ File Formats: Comprehensive support for documents (PDF, DOCX), images (PNG, JPEG, WebP),
videos (MP4, AVI), audio (MP3, FLAC), archives (ZIP, RAR), and many more.
- Privacy-First: All file analysis happens locally in your browser. Your files
never leave your computer, and we don't store or transmit any data.
- Lightning Fast: Powered by Rust and WebAssembly, our detector analyzes files in milliseconds
by reading only the file header, not the entire file.
- Ransomware Detection: Built-in security feature that warns you if a file appears to be
encrypted by ransomware based on known ransomware file signatures.
- Parent Format Detection: Shows the base format for specialized file types (e.g., DOCX is based on ZIP).
- No Installation Required: Works directly in your browser on any device - Windows, Mac, Linux,
Android, or iOS.
Common Use Cases
- Identify files with missing or incorrect extensions
- Verify unknown files downloaded from the internet
- Confirm that renamed files are what they claim to be
- Detect file type mismatches that could indicate malware
- Determine correct MIME types for web development projects
- Analyze formats for data recovery and forensic purposes
- Verify file authenticity before opening email attachments
- Process bulk files in automated workflows
Technical Details
Our detector uses the mimetype-detector Rust library compiled to WebAssembly for maximum performance and security.
The tool reads only the first 64KB of your file (the header section) to identify its type, making detection extremely
fast even for large files. The detection algorithm matches magic bytes and binary signatures against a comprehensive database of
known file format patterns.
For developers: This tool is built with Rust and compiled to WebAssembly using wasm-pack. The source code demonstrates
how to create high-performance web applications using Rust's safety guarantees and WebAssembly's near-native speed.
Why Choose This Tool?
Accuracy and privacy matter. Our detector combines advanced binary analysis with complete client-side processing. Unlike other tools that upload your files to remote servers, we analyze everything entirely in your browser using WebAssembly technology. This means faster results, better privacy, and the ability to work offline once the page loads.
Whether you're a security researcher verifying file authenticity, a developer requiring accurate MIME types, or someone recovering data, this tool provides professional-grade accuracy with consumer-friendly simplicity. Try it now - completely free.
Learn More About File Formats
Expand your knowledge about file type detection and formats:
- File Formats - Comprehensive overview on Wikipedia
- MIME Types - Understanding media type standards
- File Signatures - List of magic bytes and file headers
- File Format on Wikidata - Structured data about file formats
- File Type Identification - Search Google for more techniques
- WebAssembly - Technology powering this tool