How to extract query parameters with ui-router for AngularJS?

Unless you're binding to the query parameters (see the documentation), you don't access them directly through $state or $stateParams. Use the $location service.

EDIT: Per the docs, if you want to capture query parameters in $stateParams, you can append a ? to your url, and name each query parameter, separated by &, i.e. url: "/foo?bar&baz".

See the query parameters section of the URL routing documentation.

You can also specify parameters as query parameters, following a '?':

url: "/contacts?myParam"
// will match to url of "/contacts?myParam=value"

For this example, if the url is /contacts?myParam=value then the value of $state.params will be:

{ myParam: 'value' }