File Utilities

Hashing, size conversion, format detection.

3 tools · all run in your browser

Browser-based file operations that do not need a full application: generate a cryptographic hash (MD5, SHA-1, SHA-256, SHA-512) for any file to verify integrity or fingerprint it; convert between file size units (bytes, KB/KiB, MB/MiB, GB/GiB, TB); detect the MIME type of a file by its actual bytes (magic number), not its extension — because extensions lie.

File hashing is the practical way to verify a download arrived intact. Download a software installer, drop it into the Hash Generator, and compare the SHA-256 output against the checksum published on the developer's site — if they match, the file is byte-for-byte identical to what was published. If they do not match, something was corrupted or modified in transit.

MIME type detection by magic number matters when you receive files with wrong or missing extensions, when you need to validate file types on an upload endpoint, or when a file is simply labeled ".dat" or ".bin" and you want to know what it actually is. The browser reads the first few hundred bytes and matches them against known file signatures.

All file utilities

Frequently asked

How do I verify a file download is legitimate?

Check the developer's download page for a published SHA-256 (or SHA-512) checksum. Download the file, drop it into our Hash Generator, select SHA-256, and compare the outputs character by character. If they match, the file arrived intact and unmodified.

Is MD5 still safe to use for file verification?

For detecting accidental corruption, yes. For detecting malicious tampering, no — MD5 has known collision attacks (two different files can have the same MD5 hash). Always use SHA-256 or SHA-512 when security matters.

What is the difference between KB and KiB?

KB is 1,000 bytes (decimal — used by hard drive manufacturers, network speeds, and storage marketing). KiB is 1,024 bytes (binary — used by RAM, operating systems, and most software). A "1 TB" hard drive is ~931 GiB, which is why Windows shows a smaller number than the box says.

What is a MIME type?

A standardized label for a file's content format — like text/html, image/jpeg, application/pdf, or video/mp4. Browsers and servers use MIME types to decide how to handle a file, not the file extension. Our MIME Type Detector reads the actual file bytes to identify the real type.

Can a file have the wrong extension?

Yes, frequently. A file renamed from .jpg to .png is still JPEG data — the extension changed but the bytes did not. Our MIME Type Detector reads the first few hundred bytes (the "magic number") and reports the actual format, regardless of what the extension says.