I lost my California small claims case, can I appeal?

Yes, and the specifics here surprise most people, including many defendants who assume small claims decisions are simply final. As the defendant, you're entitled to a completely new trial in the superior court, called a trial de novo, meaning the case starts over from scratch in front of a different judge rather than being reviewed for errors in the original hearing.

You have 30 days from when the clerk mails the notice of entry of judgment to file that appeal. One meaningful difference at this stage: attorneys are permitted at the trial de novo, unlike at the original small claims hearing. It's also worth knowing this appeal right belongs only to the defendant, the plaintiff has no equivalent right to appeal if they lose their own claim in small claims court.