Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text. Uses the Web Crypto API — 100% client-side.
No data sent to serverRelated Tools
What is a Hash Function?
A cryptographic hash function takes an input (called a "message") of any size and produces a fixed-size output (the "digest" or "hash") that uniquely identifies the input. A good cryptographic hash has four key properties: determinism (same input → same output every time), preimage resistance (given a hash, you cannot find the original input), collision resistance (no two different inputs produce the same hash), and the avalanche effect (changing a single bit in input flips ~50% of output bits).
What hashes are used for
- Data integrity — file checksums, Git commits, blockchain blocks
- Digital signatures — sign the hash, not the whole document
- Password storage — but only with slow hashes (Argon2, bcrypt) plus salt, NOT plain SHA-256
- Hash tables — fast lookup data structures
- Deduplication — identifying duplicate files by content
- Proof-of-work — Bitcoin mining (SHA-256 squared)
Hash vs encryption vs encoding
These three are fundamentally different. Encoding (Base64, URL encoding) is reversible without a key. Encryption (AES, RSA) is reversible with a key. Hashing is one-way — designed to be impossible to reverse, even with infinite compute. Confusing these is the source of many security bugs.
⚠️ Reference Only
Output is generated based on your input and is provided for reference. Results may vary depending on your specific use case, edge cases, or environment-specific behavior. We do not guarantee accuracy of conversions, validations, or computed values.
Always verify critical outputs against official documentation or production environments. We are not responsible for any decisions or losses based on these tool results.
📖 Related Guides
JWT Anatomy — Header, Payload, Signature
Understand JWT structure, claims, and signing algorithms. Security best practices.
URL Encoding — When to Use What
encodeURI vs encodeURIComponent vs escape. Query strings, paths, and reserved characters.
Hash Algorithms — MD5, SHA-1, SHA-256, bcrypt
When to use each hash function. Security comparison and password storage best practices.