The Crypto interface represents basic cryptography features available in the current context. It allows access to a cryptographically strong random number generator and to cryptographic primitives.

Note: This feature is available in Web Workers

The Web Crypto API is accessed through the Window.crypto property, which is a Crypto object.


This interface implements properties defined on RandomSource.

Crypto.subtle Read only Secure context

Returns a SubtleCrypto object providing access to common cryptographic primitives, like hashing, signing, encryption, or decryption.


This interface implements methods defined on RandomSource.


Fills the passed TypedArray with cryptographically sound random values.

Usage notes

You should avoid using the Web Crypto API on insecure contexts, even though the Crypto interface is present on insecure contexts, as is the Window.crypto property. In addition, the Crypto method getRandomValues() is available on insecure contexts, but the subtle property is not.

In general, you probably should just treat Crypto as available only on secure contexts.


Web Cryptography API
# crypto-interface

Browser compatibility

BCD tables only load in the browser

See also