State of California (data.ca.gov) publishes 4,585 open datasets for United States. Browse them live in Vizzie and turn any one into a map or chart.
State of California (data.ca.gov) is the open-data portal for United States, covering California. It runs on CKAN, an open catalogue standard used by many national governments. You can browse it directly at data.ca.gov.
On State of California (data.ca.gov), most datasets here are clearly licensed — only a small share are undeclared. It's important to know that "no licence declared" is not the same as public-domain or free-to-use. Undeclared data carries no explicit permission to copy, adapt, or redistribute it — so reusers should treat it cautiously and check with the publisher before relying on it. Vizzie flags each dataset's licence (or its absence) so you can see this before you build.
Of the 4,082 datasets here whose licence Vizzie can identify, essentially all of them can be used commercially; 0% are non-commercial only. Attribution is required by almost every open licence — Vizzie writes the attribution line for you when you export or publish.
No download, no GIS specialist. Opens in Vizzie.