🔐 Developer Tools

Hash & Random Generator

UUIDs, cryptographic hashes, random data, passwords, API keys, JWT tokens, and encoding utilities — all computed locally in your browser.

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Generator

UUID v4

No settings required — click Generate New to produce a fresh UUID.

Output
Click Generate to produce output…

UUID V4 · RFC 4122 compliant

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100% private: everything is computed locally in your browser — no input is ever uploaded. SHA-1/256/384/512 and HMAC use the native Web Crypto API; MD5 uses a standard RFC 1321 implementation; random values use the crypto.getRandomValues() CSPRNG. Note: MD5 and SHA-1 are not collision-resistant — use SHA-256 or stronger for security-sensitive work.

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UUID v1/3/4/5

RFC 4122

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Hash Functions

MD5 · SHA-*

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Passwords & Keys

Configurable

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Encode / Decode

Base64 · URL · Hex

Overview

Generate Hashes, UUIDs, Tokens, and Encoded Data Locally in Your Browser

The Hash and Random Generator covers the full range of developer token needs in a single tool: cryptographic hashes (MD5, SHA-1, SHA-256, SHA-384, SHA-512), all four UUID versions (v1 time-based, v3 MD5 namespace, v4 random, v5 SHA-1 namespace), random strings, passwords, API keys, and signed JWT tokens. Every computation runs locally — SHA-1 through SHA-512 and HMAC use the browser-native Web Crypto API (SubtleCrypto), MD5 uses a faithful RFC 1321 implementation because Web Crypto does not expose MD5, and all randomness is drawn from crypto.getRandomValues() so outputs are cryptographically unpredictable.

The Encode/Decode section handles Base64 (with proper UTF-8 support via TextEncoder/TextDecoder), hexadecimal encoding, URL percent-encoding, and HTML entity encoding and decoding. A history panel keeps the last 20 generations so you can refer back or export them as CSV — all without a page reload or any network call.

100% freeNo sign-upNothing uploadedWeb Crypto API
How to use it
  1. 1Choose a category tab — UUID, Hash, Random, or Encode/Decode — and then select the specific type from the pill row underneath.
  2. 2For generators that need no input (UUID v1/v4, random string, password, API key), the result is produced automatically on tab selection. Click Generate New for a fresh value.
  3. 3For hash functions (MD5, SHA-1, SHA-256, SHA-384, SHA-512), type or paste the text you want to hash and click Convert.
  4. 4For JWT tokens, enter the payload JSON, a secret key, and choose HS256, HS384, or HS512; the token is signed locally using HMAC via Web Crypto.
  5. 5Click the Copy button next to any output to copy it to the clipboard instantly.
Key features
  • SHA-1, SHA-256, SHA-384, and SHA-512 computed via the browser-native SubtleCrypto API — no third-party library required.
  • MD5 implemented as a standard RFC 1321 pure-JavaScript function, since Web Crypto does not provide MD5.
  • All random values — strings, hex, passwords, API keys, UUIDs — generated using crypto.getRandomValues() (a CSPRNG), never Math.random().
  • JWT signing with HS256, HS384, and HS512 using HMAC via Web Crypto; JWT decode reads any token's header and payload without verification.
  • UUID v1 (60-bit millisecond timestamp via BigInt), v3 (MD5 namespace), v4 (random), and v5 (SHA-1 namespace) following RFC 4122.
  • Base64 encode and decode with correct UTF-8 handling using TextEncoder and TextDecoder for non-ASCII characters.
  • Generation history panel retaining the last 20 outputs, with CSV export and one-click copy for any previous result.

Frequently asked questions

Is MD5 safe to use for passwords or security checks?
No. MD5 (and SHA-1) are not collision-resistant, meaning two different inputs can produce the same hash. Use SHA-256 or stronger for any security-sensitive purpose such as password hashing or data integrity checks.
Does anything get sent to a server when I hash text?
Nothing is uploaded. All hashing, encoding, and generation runs entirely in your browser tab using the Web Crypto API and pure JavaScript. No data leaves your device.
Are the generated passwords and API keys truly random?
Yes. All random output uses crypto.getRandomValues(), which is the browser's cryptographically secure pseudo-random number generator (CSPRNG), not the predictable Math.random() function.
What is the difference between UUID v3, v4, and v5?
UUID v4 is purely random. UUID v3 and v5 are deterministic: given the same namespace UUID and name string, they always produce the same UUID. v3 uses MD5 and v5 uses SHA-1 as the internal hash function.
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Full guide

Hash Generator Complete Guide

Learn the difference between MD5, SHA-256, HMAC, UUID, and when to use each hash function.

MD5, SHA-256 & HMAC explainedWhen to use each algorithmCommon questions answered

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