Secure context
This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The pubKeyCredParams property of the PublicKeyCredentialCreationOptions dictionary is an Array whose elements are objects describing the desired features of the credential to be created. These objects define the type of public-key and the algorithm used for cryptographic signature operations.

If this array contains multiple elements, they are sorted by descending order of preference.


pubKeyCredParams = publicKeyCredentialCreationOptions.pubKeyCredParams


An Array whose elements are objects with the following properties:

A string describing type of public-key credential to be created. As of this writing (March 2019), only "public-key" may be used.
A numeric identifier for the algorithm to be used to generate the key pair. The links between identifier and algorithms are defined in this IANA registry (e.g. -7 indicates the elliptic curve algorithm ECDSA with SHA-256).

Though those elements are sorted by preference (the first element being the most prefered), it is up to the client to choose among those elements for building the credential.


var publicKey = {
  pubKeyCredParams: [
    // We would like an elliptic curve to be used if possible
      type: "public-key",
      alg: -7
    // If not, then we will fallback on an RSA algorithm
      type: "public-key",
      alg: -37
  challenge: new Uint8Array(26) /* this actually is given from the server */,
  rp: {
    name: "Example CORP",
    id  : ""
  user: {
    id: new Uint8Array(26), /* To be changed for each user */
    name: "",
    displayName: "John Doe",

navigator.credentials.create({ publicKey })
  .then(function (newCredentialInfo) {
    // send attestation response and client extensions
    // to the server to proceed with the registration
    // of the credential
  }).catch(function (err) {


Specification Status Comment
Web Authentication: An API for accessing Public Key Credentials Level 1
The definition of 'pubKeyCredParams' in that specification.
Recommendation Initial definition.

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Chrome Full support 67Edge Full support ≤79Firefox Full support 60IE No support NoOpera Full support 54Safari Full support 13WebView Android No support NoChrome Android Full support 67Firefox Android ? Opera Android Full support 48Safari iOS Full support 13.3Samsung Internet Android No support No


Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

See also