Google Reader is a Web-based aggregator, capable of reading Atom and RSS feeds. It was released by Google on October 7, 2005 through Google Labs. Reader was graduated from beta status on September 17, 2007.

Google made major revisions to Reader's user-interface on September 28, 2006. Product manager Nick Baum described the redesign as a movement toward making news aggregation something for the general public to enjoy. Kevin Fox, the designer of the revised Google Reader, noted that the original version was optimal for those who want to read a "river" of news. The new version took into account that most readers segment their reading by feed, group, tag, folder, or into "must read" and "maybe if I get to it" feeds.

Features of Google Reader as of 2010^[update] include:

Part of the visual redesign of all Google products in 2011, a new Google Reader interface was available on October 31, 2011. Beside the sweeping visual changes, former social features ("share" and "like" buttons) has been removed and replaced by Google+'s +1 button and the "share on Google+" box. It's said that now Reader is on its fourth social model, after using Google Talk contacts, allowing people to manage friends from the Reader interface, integrating with Google Buzz and then with Google+. The changes have been received unfavorably by multiple online blogs and technical writers, including former Google Reader product manager Brian Shih and former Google Reader lead designer Kevin Fox, and by writers in Wired,Forbes,CNET, and InformationWeek.. Over 15,000 users have signed an online petition asking Google to reinstate the original interface.