Dear Client,

I am hesitant to identify this spider.  Some of the important features used to identify spiders are the body size, orientation of the six-eight eyes, appendages at the back end of the spider. orientation of the mouthparts relative to the body.  A lot of this is a problem with the lack of contrast between features of the spider.

I would guess that this is one of the megalomorph spiders because of the body form; but it is not a tarantula (they have hairy legs!).  It may be one of the trapdoor spiders that abound in California. It is likely to be coming from under the house or at the foundation of the house.  All spiders have fangs and will bite in self-defense.  Don't handle the big spiders.  While your spider is not poisonous to humans (very few spiders in the USA are "poisonous" to humans), it will be painful if the fangs break the skin's surface.  Always treat these "puncture" wounds with care and make sure the bite site does not become infected or inflamed.  When this happens, always call and see your primary health care provider.  

Hope this helps!