GLM 5.3 Flash arrives on Mistral at Z.ai's price

Mistral added Z.ai's GLM 5.3 Flash to its API on October 22, 2026, as zai-glm-5-3-flash. It costs the same on Mistral as on Z.ai's own API: $0.15 input, $0.03 cached input and $0.50 output per million tokens.

What changed

• Mistral now serves GLM 5.3 Flash as zai-glm-5-3-flash, a multimodal mixture-of-experts model with 320B total and 18B active parameters.
• Mistral lists a 1M-token context, a 128k output limit, and text and image input.
• Mistral says the model is served without Mistral modifications.
• The weights are on Hugging Face as zai-org/GLM-5.3-Flash under the MIT license.
• Mistral retires GLM 5.2 (zai-glm-5-2) on its platform on October 31, 2026 and points users to GLM 5.3 (zai-glm-5-3) at the same price.

Z.ai released GLM 5.3 Flash on its own platform in August 2026. The October 22 change adds Mistral as a place to call it.

Pricing at the source

Prices per million tokens, from each vendor's pricing page:

GLM 5.3 Flash on RouterPlus today

RouterPlus lists GLM 5.3 Flash on 10 providers. Mistral is not one of them. Prices per million tokens, from the live catalog on October 31, 2026:

Full list: GLM 5.3 Flash API pricing.

What to do

• Calling GLM 5.2 on Mistral: Mistral's named replacement is zai-glm-5-3, at the same price. See GLM 5.3 API pricing.
• Calling GLM 5.3 Flash through RouterPlus: use the model ID z-ai/glm-5.3-flash with one API key at https://api.routerplus.com/v1. Sign up at app.routerplus.com/login and call the API right away.

Sources

1. Mistral changelog
2. Mistral docs: Z.ai GLM 5.3 Flash
3. Z.ai pricing
4. Z.ai: GLM-5.3-Flash announcement
5. GLM-5.3-Flash on Hugging Face
6. RouterPlus model catalog