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The SubtleCrypto.encrypt() method returns a Promise of the encrypted data corresponding to the cleartext, algorithm and key given as parameters.


var result = crypto.encrypt(algo, key, cleartext);


  • algo is an object defining the encryption function to use or a DOMString, the latter being a shorthand for {"name": algo}. Supported values are:
    • {"name": "AES-CBC", iv} where iv is an ArrayBuffer or an ArrayBufferView with 16 random bytes (these should be generated by RandomSource.getRandomValues()).
    • {"name": "AES-CTR", counter, length}
    • {"name": "AES-GCM", iv, additionalData, tagLength} (additionalData and tagLength are optional)
    • {"name": "RSA-OAEP", label} (label is optional)
  • key is a CryptoKey containing the key to be used for signing.
  • cleartext is a ArrayBuffer or an ArrayBufferView containing the data to be encrypted, the cleartext.

Return value


The promise is rejected when the following exception is encountered:

  • InvalidAccessError when the encryption key is not a key for the requested encryption algorithm or when trying to use an algorithm that is either unknown or isn't suitable for encryption.


Specification Status Comment
Web Cryptography API
The definition of 'SubtleCrypto.encrypt()' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 37 34 (34) Not supported ? Not supported
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) 37 34.0 (34) Not supported ? Not supported

See also

Document Tags and Contributors

 Contributors to this page: Wladimir_Palant, pstricker, TheRealJZ, teoli, kjannis
 Last updated by: Wladimir_Palant,