The California Department of Justice will use information submitted to create a record of potential illegal conduct by federal agents that could be used in possible legal actions.
"This new portal gives Californians an easy and safe way to speak up, share what they see, and help us hold people accountable. No one is above the law," Gov. Gavin Newsom said in a statement.
Videos and photos of potential misconduct can be submitted through the portal.
"While federal agents have the authority to enforce federal law, they must do so lawfully," California Attorney General Rob Bonta said. "Federal agents may definitely enforce the law in a lawful manner, but they must follow the Constitution, and they're not above accountability."
Immigration raids in Southern California ramped up over the summer and spread fear in immigrant communities, prompting many to limit their outings.
Federal agents have rounded up immigrants without legal status to be in the U.S. from Home Depots, car washes, bus stops, and farms. Some U.S. citizens have also been detained.
The Associated Press contributed to this report.