Z.ai said GLM-5.1 is now available to all GLM Coding Plan users and highlighted a 5am to 11am PT switch window. The update broadens access beyond the initial rollout, though early practitioner tests reported weaker Repo bench and tool-calling behavior than 5.0.
The concrete change is broad availability. Z.ai's launch post says GLM-5.1 is now open to all GLM Coding Plan users, and the linked plan page describes that plan as AI coding for "Agents & IDEs" with API keys included. The image attached to the post shows Z.ai benchmarking GLM-5.1 at 45.3 on a "Coding Evaluation" using Claude Code as the harness, up from 35.4 for GLM-5 but still below Claude Opus 4.6 at 47.9 [img:0|Coding evaluation].
Z.ai's follow-up post added an operational detail: from 5 am to 11 am PT, users can "switch over to the GLM Coding Plan," which it said would "take some of the load off Claude." That reads more like a usage window than a permanent routing change, and the post does not spell out rate limits or billing behavior.
The first practitioner check-in was less bullish than the launch framing. In early testing, RepoPrompt's author wrote that 5.1 "does worse on Repo bench" and "doesn't seem to follow instructions as reliably in terms of tool calling," while still reporting that the model was already usable inside the RepoPrompt agent.
GLM-5.1 is available to ALL GLM Coding Plan users! z.ai/subscribe Show more
Early testing of 5.1 disappointed me a bit. I think it’s a smaller model than 5.0 It does worse on Repo bench and doesn’t seem to follow instructions as reliably in terms of tool calling. Still seems like a great coder though, and you can use it in @RepoPrompt agent right now!
Don't panic. GLM-5.1 will be open source.
