UUIDs, cryptographic hashes, random data, passwords, API keys, JWT tokens, and encoding utilities — all computed locally in your browser.
Generator
No settings required — click Generate New to produce a fresh UUID.
6a94e0c3-9927-4357-baa2-8ecf93a713e0
UUID V4 · RFC 4122 compliant
Demo tool: Hash functions (MD5, SHA-*) and JWT are simplified implementations — not cryptographically secure. For production security use the Web Crypto API or a trusted library. Random values use Math.random(); use crypto.getRandomValues() for security-critical code.
UUID v1/3/4/5
RFC 4122
Hash Functions
MD5 · SHA-*
Passwords & Keys
Configurable
Encode / Decode
Base64 · URL · Hex
A hash generator converts input data into a fixed-length string using algorithms like MD5, SHA-1, SHA-256, and SHA-512. Hashes are one-way functions — the original data can't be recovered from the output — making them essential for data integrity verification and checksums. This tool also provides UUID generation, encoding/decoding utilities, JWT helpers, and secure password creation, all computed locally in your browser.
MD5 produces a 128-bit hash and is considered cryptographically broken for security. SHA-256 (SHA-2 family) produces a 256-bit hash and is widely used in SSL, blockchain, and security applications. For any security-sensitive use case, prefer SHA-256 or higher.
Yes. All operations run entirely in your browser — no data is transmitted to any server and nothing is stored beyond the current session.
UUID v4 (random) suits most use cases. v1 is timestamp-based and useful when ordering matters. v3 and v5 are deterministic from a namespace + name — prefer v5 (SHA-1 based) over v3 (MD5 based) for better collision resistance.
Generated passwords and API keys use configurable character sets and are suitable for development and testing. For production password hashing, use dedicated libraries like bcrypt or Argon2 on the server side.
HMAC combines a hash function with a secret key to verify both message integrity and authenticity. Common uses: API request signing, webhook verification, and session token validation.
A hash generator applies a cryptographic hash function to any input — text, a password, or a file — and produces a fixed-length string of hexadecimal characters called a digest. Three key properties define a good hash function: it is deterministic (same input always gives same output), one-way (impossible to reconstruct the input from the hash), and exhibits the avalanche effect (changing even one character completely changes the hash output).
It is essential to distinguish hashing from encryption and encoding. Encryption is two-way — data can be unscrambled with the correct key. Encoding (like Base64) is also reversible and is about data format, not security. Hashing is irreversible by design. Common algorithms: MD5 (128-bit) and SHA-1 (160-bit) are fast but cryptographically broken. SHA-256 and SHA-512 remain robust for integrity checking. For passwords, purpose-built slow algorithms like bcrypt, scrypt, or Argon2 are required.
Hash generators are used daily across software. Download pages list SHA-256 checksums so users can verify files were not tampered with. Databases store password hashes so a breach does not expose plaintext credentials. Git uses SHA-1 (transitioning to SHA-256) to uniquely identify every commit. CDNs use hashes for cache-busting — appending a file hash to its URL ensures browsers always fetch the latest version.
MD5 was designed in 1991 and produces a 128-bit (32 hexadecimal character) digest. It became popular for its speed but researchers demonstrated practical collision attacks in 2004. This makes MD5 unsuitable for security-sensitive purposes. It is still used as a fast, non-cryptographic checksum for detecting accidental data corruption where collision resistance is not required.
No — and neither is any raw unsalted hash including SHA-256. Modern GPUs compute billions of MD5 hashes per second, making brute-force attacks practical. For passwords, always use bcrypt, scrypt, or Argon2id — algorithms designed to be slow and configurable in cost. Never implement your own password hashing scheme.
Find the expected hash on the official download page (usually labeled "SHA-256 checksum"). Then generate the hash of your downloaded file using this tool or a command-line utility (sha256sum on Linux/macOS, Get-FileHash in PowerShell on Windows). Compare the two strings exactly — any differing character means the file is corrupt or tampered with.
SHA-256 (producing a 256-bit digest) is one of the most widely deployed hash functions. It secures HTTPS connections as part of TLS certificate signatures, powers Bitcoin's proof-of-work algorithm, is used in code-signing certificates, and underpins HMAC-SHA256 — the default JWT signing algorithm. It remains unbroken and is the recommended general-purpose hash function.
A JSON Web Token (JWT) is a compact token format for representing claims between two parties, most commonly for authentication. A JWT has three Base64URL-encoded parts: a header (algorithm and type), a payload (claims like user ID and expiry), and a signature. The signature is produced by applying HMAC-SHA256 to the header and payload using a secret key, so the server can verify tokens without storing session state in a database.
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