A petition to save the service, which aggregates news content from web feeds, had 25,000 signatures in a few hours.
Experts say shutting Reader is part of Google’s plan to migrate more people to its social media service, Google+.
Google said in its official blog: “There are two simple reasons for this – usage of Google Reader has declined, and as a company we are pouring all of our energy into fewer products.”
It added users and developers who wanted to use alternatives could export their data, including their subscriptions over the next four months, using its Google Takeout service.
Google Reader launched in 2005, when Really Simple Syndication (RSS) feeds were a new way to keep tabs on favourite websites and blogs.
The news of its demise has led to a debate about the service on Twitter. Some said its launch had effectively destroyed other RSS competitors.
Security consultant @cortesi tweeted: “Google – a destroyer of ecosystems”.
In his blog, he added:” “Google destroyed the RSS feed-reader ecosystem with a subsidised product, stifling its competitors and killing innovation.
“It then neglected Google Reader itself for years, after it had effectively become the only player.”
Adam Leach, a principal analyst at research firm Ovum, said Google’s business model was to offer free services in order to draw people into its other offerings.
Now, he said, Google wanted people to experience their favourite websites in a more social way and was seeking to migrate its aggregation platforms to its social media service.
“This has been on the cards for a while. It is part of Google’s strategy to shift people to Google + and other social tools,” he said.