File mime type checker

File MIME Type Checker — Detect True File Format Online

Detect the true MIME type of any file by analyzing its binary signature (magic bytes), not just the file extension. File extensions can be changed or spoofed — this tool reads the actual file header to determine the real format. Essential for security-conscious file upload handling, content validation, and format verification workflows.

MIME Type Detection Use Cases

• Security validation of uploaded files in web applications
• Detecting disguised malicious files with misleading extensions
• Verifying media file formats before processing
• Content-Type header validation for API development
• Digital forensics and file system analysis
• Automated media processing pipeline validation

True MIME type detection via magic bytes is a critical security layer for any application accepting file uploads. A file renamed from .exe to .jpg is still an executable — magic byte analysis reveals the truth. Use this tool to verify files before processing, identify corrupted media, investigate suspicious files, and validate content-type claims in API integrations. All analysis is performed client-side for privacy.