Amazon.com Inc.'s grocery delivery service is rolling into San Francisco.

The says it is expanding its AmazonFresh into the city after testing it in Los Angeles and Seattle. The service provides same-day and early-morning delivery of more than 500,000 Amazon products including fresh groceries and local items.

Other companies have been expanding their online grocery delivery services for customers who want to avoid the supermarket. Competitors include FreshDirect, Instacart, Peapod and Safeway.

AmazonFresh shipping is free for orders over $35, but users have to pay $299 a year for the service. Amazon is giving customers in San Francisco a free 30-day trial.

AmazonFresh was launched in Seattle in 2007. It came to Los Angeles in June.