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AES Key Generator

Generate a cryptographically secure 128-bit or 256-bit AES key directly in your browser. Keys are never sent to any server — all generation happens locally using the WebCrypto API.

Key Size

Your AES-256 Key (64 hex characters)

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Compatible with the Locki encryption format

Algorithm
AES-256-GCM
Key length
256 bits / 64 hex chars
Crypto API
WebCrypto (browser-native)
Privacy
Generated locally, never transmitted

What is an AES Encryption Key?

An AES key is a random secret value used to encrypt and decrypt data. The same key that locks your data is required to unlock it — without it, the content is permanently unreadable. Keys are represented as hexadecimal strings: 128-bit keys are 32 characters long, 256-bit keys are 64 characters.

128-bit vs 256-bit

AES-128

16 bytes · 32 hex characters

Fast and computationally secure for all practical purposes. Widely used in TLS, disk encryption, and consumer applications. A good choice when performance or compatibility is a priority.

AES-256

32 bytes · 64 hex characters

Larger security margin and required by government and high-compliance standards (NIST, FIPS). The format used by Locki. Recommended when handling sensitive business or regulated data.

What are AES keys used for?

AES keys power symmetric encryption — one key encrypts, the same key decrypts. Common use cases:

  1. 01Encrypt messages before sending over Slack, email, or Notion
  2. 02Protect API keys, passwords, and credentials shared across teams
  3. 03Secure file contents before uploading to cloud storage
  4. 04Gate sensitive data so only people with the correct key can read it
AES-GCM Encrypt & Decrypt Text OnlineFeatures

Questions about this tool

Is this AES key generator safe to use?
Yes. Keys are generated in your browser with the cryptographically secure random generator of the Web Crypto API. Nothing is sent to a server.
What is the difference between a 128-bit and a 256-bit AES key?
A 128-bit key is 16 bytes (32 hexadecimal characters); a 256-bit key is 32 bytes (64 hexadecimal characters). Both are considered secure. AES-256 gives a larger security margin and is the usual choice for long-lived secrets.
What format is the key in?
Hexadecimal. A 256-bit key is a string of 64 characters from 0–9 and a–f, ready to paste into a library, an environment variable or the Locki extension.
Can I use these keys outside Locki?
Yes. They are standard AES keys and work with any AES-GCM implementation, including OpenSSL, Node.js crypto and the Web Crypto API.