File Type & Magic Bytes Checker
Analyze binary magic bytes, true MIME types, and header signatures. Unmask disguised file extensions and view raw hex offsets safely in your browser.
Drop any file to inspect magic bytes
Instantly analyzes header signatures, true MIME type, and detects disguised extensions or malware spoofing.
How to Use File Type & Magic Bytes Checker
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Drop any file or document
Select or drag any unknown, corrupted, or extensionless file into the inspector dropzone.
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Automatic magic bytes inspection
The tool reads the first 64 bytes of the binary header directly in your browser without uploading anything.
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Verify signature & copy hex dump
Check the detected true MIME type, examine potential extension spoofing, and inspect the raw hex and ASCII offsets.
Disguised Executable Check Example
contract_signed.pdf (Renamed .exe file)Flagged Mismatch: Header contains "4D 5A" (Windows Executable PE) disguised as PDFProtects against malicious file extension spoofing.
Technical Specifications
- Supported Inputs: Any binary file, PDF, PNG, JPG, WEBP, ZIP, DOCX, XLSX, MP3, WAV, MP4, EXE
- Input Limit: Unlimited client-side computation (reads first 64 bytes)
- Processing Engine: 100% In-Browser (FileReader Binary ArrayBuffer)
- Content Uploads: None (Your files and text are processed locally on your device with zero uploads)
Privacy & Security Guarantee
Your binary files are processed entirely in your web browser's memory using native client-side web technologies. Unlike traditional cloud tools, your content is never uploaded to remote servers, stored on external disks, or analyzed by third parties.
2ClickKit In-Browser vs Traditional Cloud Tools
| Feature | 2ClickKit (In-Browser) | Traditional Cloud Services |
|---|---|---|
| Data Privacy | Files never leave your local device | Uploaded to remote servers and third-party clouds |
| Processing Speed | Instant local execution (0ms upload time) | Constrained by internet upload & server processing queues |
| Account & Costs | 100% Free with zero registration or paywalls | Tiered subscriptions, limits, or forced sign-ups |
Best Practices & Tips
- Use this tool whenever an email attachment looks suspicious or Windows refuses to open a file with a missing or damaged extension.
- Need to encode a verified file into base64 for embedding in CSS or HTML? Check our Base64 File Encoder.
Frequently Asked Questions
What are file magic bytes?
Magic bytes are specific binary signatures located at the very beginning of a file (the header) that uniquely identify its true format, regardless of what file extension is shown in the operating system.
How does it detect extension spoofing or disguised malware?
If an executable file (e.g. .exe starting with "MZ" bytes) is maliciously renamed to invoice.pdf or image.png, the tool compares the internal byte signature with the reported file extension and flags the mismatch immediately.
Are my files uploaded to any server or cloud API?
No! All binary reading uses the native browser FileReader API on your local machine. 0 bytes leave your computer.
What file formats can it identify?
It detects PDF, PNG, JPEG, GIF, WebP, ZIP, Office documents (DOCX, XLSX, PPTX), 7Z, GZ, RAR, MP3, WAV, OGG, FLAC, MP4, WebAssembly, Windows executables, and plain text formats.