Hash Generator (MD5, SHA-256, SHA-512)
Generate MD5, SHA-1, SHA-256, SHA-384, SHA-512 and CRC32 hashes or HMACs for text and files, and verify checksums. Files are hashed locally and never uploaded.
- Upload
- Options
- Download
- ✓ 100% free
- ✓ No sign-up
- ✓ No limits
- 🔒 Files never leave your device
How to: Hash Generator
- Type text or choose a file.
- All hashes are calculated instantly.
- Paste an expected hash to verify a download.
A hash is a short fingerprint of data: change even one bit and the hash changes completely. Hashes are used to verify downloads, detect duplicate files, store passwords securely (with special slow algorithms) and sign API requests. This generator calculates the common algorithms for any text or file and can confirm that a file matches the checksum published by its author.
Common uses
- Verify that a downloaded installer or ISO matches the SHA-256 checksum on the official site.
- Generate HMAC-SHA256 signatures to test webhook and API authentication.
- Find duplicate files by comparing their hashes.
- Create cache keys and ETags during development.
Tips for best results
- Copy the expected checksum into the compare box – a green row confirms the match.
- Hashes of text depend on exact bytes; a trailing space or line break gives a different result.
- Never store passwords as plain MD5 or SHA hashes; use bcrypt, scrypt or Argon2.
- CRC32 is for detecting accidental errors only, not tampering.
How hashes are calculated here
SHA-1 and the SHA-2 family use your browser's built-in Web Crypto API, the same audited code used for HTTPS. MD5 and CRC32 are implemented in JavaScript because browsers do not provide them. Text is converted to UTF-8 bytes first, which matches the output of command-line tools such as sha256sum on Linux and macOS or Get-FileHash in Windows PowerShell.
HMAC for APIs
An HMAC combines a secret key with the message, so only someone with the key can produce the same value. Payment providers, chat platforms and cloud services use HMAC-SHA256 to sign webhooks. Enter the key in the options to generate HMACs for SHA-1, SHA-256, SHA-384 and SHA-512 and compare them with the signature your server receives.
Why use FreePDF for Hash Generator?
| FreePDF | Typical upload-based sites | |
|---|---|---|
| What you type is sent to a server | No – stays in your browser | Often |
| Sign-up required | Never | Often for bigger jobs |
| Hourly / daily task limits | None | Common on free plans |
| Works offline after loading | Yes, for most tools | No |
Frequently asked questions
Which hash should I use
Use SHA-256 or SHA-512 for integrity checks and security. MD5 and SHA-1 are broken for security purposes but are still used to match legacy checksums.
Can I hash large files
Yes, files of several hundred megabytes work on most computers because hashing happens locally in your browser; very large files depend on available memory.
Is Hash Generator really free?
Yes. Every tool on FreePDF is 100% free with no file limits, no sign-up and no watermarks. The site is supported by unobtrusive ads.
Are my files uploaded to a server?
No. FreePDF processes your files directly in your browser using JavaScript. Your documents never leave your device, so they stay completely private.
Does it work on mobile?
Yes. FreePDF works in any modern browser on Android, iPhone, iPad, Windows, Mac and Linux.