OpenAI’s popular AI chatbot, ChatGPT, resumed service after a brief outage impacted thousands of users, the company confirmed on Friday.

“ChatGPT issues have now been resolved,” OpenAI announced on its website. Access was restored for most users by 4:34 p.m. PT (0034 GMT on Saturday), with a few still experiencing issues until around 5 p.m. (0100 GMT on Saturday).

OpenAI CEO Sam Altman shared on X (formerly Twitter) that ChatGPT had been down for about 30 minutes, adding a frown emoji and noting, “We’re much more reliable than before, but there’s still work ahead.”

Outage tracking site Downdetector.com reported that the outage affected over 19,403 users around 7:13 p.m. ET (0013 GMT on Saturday).

Since ChatGPT’s launch in November 2022, the chatbot has grown to 250 million weekly active users. OpenAI’s valuation has skyrocketed to $157 billion from $14 billion in 2021, with revenues reaching $3.6 billion, far exceeding Altman’s initial estimates.