Hash Generator
Generate cryptographic hashes for any text — SHA-256, SHA-512, SHA-1. Uses browser Web Crypto API, nothing sent to server.
Not available in Web Crypto API — MD5 is not supported by browsers' built-in crypto for security reasons. What are cryptographic hashes?
A cryptographic hash function takes any input and produces a fixed-length output (the hash or digest). The same input always produces the same output, but even a tiny change in input produces a completely different hash — making hashes useful for data integrity verification, password storage, and digital signatures.
Common use cases
Generate a hash of a file's contents to verify it hasn't been tampered with or corrupted during transfer.
Websites store the hash of your password, not the password itself. On login, the entered password is hashed and compared.
Sign a hash of a document rather than the document itself — faster and the signature still proves the content is unchanged.
Frequently asked questions
Is my text sent to any server?
No. This tool uses the browser's built-in Web Crypto API (window.crypto.subtle) which runs entirely in your browser. Your input never leaves your device.
Why is MD5 not available?
The Web Crypto API intentionally does not support MD5 because it is considered cryptographically broken — collisions (two different inputs with the same hash) can be found quickly. For any security-sensitive use, MD5 should be avoided entirely.
Can I reverse a hash to get the original text?
No. Hash functions are one-way by design. You cannot reverse SHA-256 or SHA-1 to get the original input. Short or common inputs can sometimes be found via rainbow tables (precomputed hash lookups), which is why passwords should be salted before hashing.
What is the difference between SHA-1 and SHA-256?
SHA-1 produces a 160-bit (40 hex char) output and has known theoretical weaknesses. SHA-256 produces a 256-bit output and is currently considered secure. For new applications always prefer SHA-256 or SHA-512.
Why does the same text always produce the same hash?
Hash functions are deterministic — given the same input, they always produce the same output. This is what makes them useful for verification: if the hash matches, the data is identical. Even a single character change produces a completely different hash.