Free Online Hash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text. Uses the Web Crypto API for cryptographically accurate results with one-click copy.
What Is a Hash Function?
A cryptographic hash function takes an input of any size and produces a fixed-size string of characters that appears random. The same input always produces the same hash, but even a tiny change in the input produces a completely different hash. Hash functions are one-way — you cannot reverse a hash to recover the original text.
SHA Hash Algorithms Explained
SHA (Secure Hash Algorithm) is a family of cryptographic hash functions. SHA-1 produces a 160-bit (40 hex character) hash and is considered deprecated for security purposes. SHA-256 produces a 256-bit (64 hex character) hash and is widely used in TLS certificates, Bitcoin, and file integrity verification. SHA-384 and SHA-512 produce longer hashes for applications requiring extra security margin.
Common Uses for Hash Functions
Hashes are used for password storage (never store plain-text passwords), data integrity verification (ensuring files have not been tampered with), digital signatures, blockchain technology, and deduplication. When comparing files or verifying downloads, matching hashes confirm the content is identical to the original.
Frequently Asked Questions
Which hash algorithm should I use?
SHA-256 is the most commonly recommended for general use. SHA-1 is deprecated for security-sensitive applications. Use SHA-512 when you need extra security margin, such as for password hashing or high-security file verification.
Can a hash be reversed?
No. Cryptographic hash functions are one-way. You cannot derive the original input from a hash. However, common short inputs can be found via rainbow tables, which is why passwords should be salted before hashing.
Why are there different hash lengths?
Different algorithms produce different output lengths: SHA-1 is 40 hex characters, SHA-256 is 64, SHA-384 is 96, and SHA-512 is 128. Longer hashes provide a larger output space, reducing the probability of two different inputs producing the same hash (collision).
Is SHA-1 still safe to use?
SHA-1 is considered broken for collision resistance and should not be used for security-critical applications like TLS certificates or digital signatures. It is still acceptable for non-security purposes like checksums or data identification.
Is my text sent to a server?
No. All hashing is performed entirely in your browser using the Web Crypto API (crypto.subtle.digest). Your text never leaves your device.