Developer Cryptography & Security Tools

All tools run client-side in your browser using the Web Crypto API. No data is sent over the network, ensuring zero exposure for keys, passwords, and tokens.

Primary Tool

JWT Secret Key Generator

Generate cryptographically secure 128-bit to 512-bit signing secrets for HMAC-SHA256, HS384, and HS512 with entropy metrics and encoding options.

Web Crypto API (crypto.getRandomValues)

128, 192, 256, 384, and 512-bit key lengths

Hex, Base64, Base64URL, and UTF-8 encodings

Real-time entropy bit and byte calculations

RFC 7518 algorithm compliance guidance

Zero remote network transmission

Open JWT Secret Generator

Essential

JWT Decoder

Decode JSON Web Tokens instantly and securely in your browser. Inspect Header, Payload claims, timestamps, and signature without sending tokens to any server.

100% client-side Base64URL and UTF-8 decoding

Header, Payload, and Signature visual breakdown

NumericDate timestamp conversion with relative times

Active, expired, and not-yet-valid claim status badges

Malformed token diagnostics & syntax error detection

Zero token persistence or network transmission

Open JWT Decoder

Utility

High-Entropy Secret Key Generator

Generate cryptographically random passwords, API tokens, session keys, and encryption secrets with custom character sets and entropy scoring.

Custom character length (8 to 256 characters)

Character set toggles: lowercase, uppercase, numbers, symbols

Avoid ambiguous characters option (l, 1, I, O, 0)

Calculated Shannon entropy in bits

Bulk key generation support (up to 20 keys at once)

Open Secret Key Generator

RFC 4122

UUID v4 Generator

Generate cryptographically secure RFC 4122 Version-4 UUIDs directly in the browser with single or bulk batch generation.

RFC 4122 compliant version 4 UUID generation

Uses window.crypto.getRandomValues for true randomness

Format options: with/without hyphens, uppercase/lowercase

Bulk generation (1 to 50 UUIDs at once)

One-click copy all or individual UUIDs

Open UUID Generator

RFC 4648

Base64 & Base64URL Encoder / Decoder

Encode and decode text to standard Base64 and URL-safe Base64URL with UTF-8 character encoding support for developer workflows.

Standard Base64 and RFC 7515 Base64URL variants

Full UTF-8 support (Unicode, emojis, international characters)

Live bi-directional encoding and decoding

Character and byte count metrics

Safe error messaging for malformed Base64 strings

Open Base64 Encoder / Decoder

SubtleCrypto

Web Crypto Hash Generator

Compute SHA-256, SHA-384, SHA-512, and SHA-1 cryptographic hashes locally using the native browser SubtleCrypto engine.

SHA-256, SHA-384, SHA-512, and SHA-1 algorithms

Zero-latency browser calculation via crypto.subtle.digest

Compares multiple hash algorithms side by side

Hex output with byte lengths and bit lengths

Security guidance on collision resistance and deprecated algorithms

Open Hash Generator