Open-weight & challenger labs
Zhipu AI (Z.ai / GLM)
Known for competitive benchmark performance and a free small-model tier.
Checked September 19, 2026
No lab publishes a real roadmap
So this page keeps three things apart on purpose. What has already shipped is dated. What is coming is listed only where the lab itself has said it in public, with the source named. Everything else sits under “What to watch” and is my own read of their shipping pattern — informed guessing, not news. If a date matters to you, check the lab's own page linked above.
What they are
Zhipu AI, which trades as Z.ai, is known for competitive benchmark results and for listing a free small-model tier on its own pricing page.
Its open-weight record is real but one generation behind: older GLM-4.x models are open, and the current flagship's status is unconfirmed.
What they currently ship
Every model in the directory entry, with its free-tier status.
- GLM-5.3— Current flagship with strong general and coding performance; API-only.Paid only
- GLM-4.5-Flash (and related Flash-tier models)— Zhipu’s own pricing lists these at $0 per token.Free
- Note: Older GLM-4.x generations are open-weight; GLM-5.3’s open-weight status is unconfirmed as of this writing.
What you get for free
The honest version, in one paragraph.
Unusually literal: the Flash-tier models are priced at zero on the company's own pricing page, which makes them free to call rather than merely free to download. The flagship is paid and API-only, and older open-weight generations are available if you want to self-host.
Track record
Things that actually happened, oldest first, each with a date.
- 2023–2024The GLM family establishes itself, with several generations published as open weights.
- 2025GLM-4.5 and its Flash tiers ship, with Flash-tier pricing listed at zero.
- 2026GLM-5.3 arrives as the current flagship, API-only.
Confirmed and announced
Only what the lab has stated in public. Nothing here rests on a rumor.
GLM-4.5-Flash and related Flash-tier models are listed at $0 per token on Zhipu's own pricing.
Stated on the lab's own pricing or docs page
What to watch
My own read of where this lab is heading, based on how it has shipped so far. Not announcements — treat these as questions to check, not facts.
- — Whether GLM-5.3 weights are ever published — as of this writing that is unconfirmed, and we won't guess either way.
- — Whether the $0 Flash tier survives, since a free-priced hosted model is unusual and easily withdrawn.
- — Rate limits on the free tier, which matter more than the headline price.
Their ethics and safety policies
What Zhipu AI (Z.ai / GLM) has published about safety and ethics, the documents themselves, what those documents leave out — and my own read, kept separate.
Looking for which tool to actually use? See AI Models Compared