vs
Modal vs Z.ai
Z.ai sells open-weight GLM models and an $18 coding plan. Modal rents per-second GPUs for whatever model you bring. A ready API versus a compute platform.
By The Subconscious Team · Updated
Modal vs Z.ai: key differences
Z.ai is the international brand of Zhipu AI, maker of the GLM models. GLM-5.3 costs $1.40 in and $4.40 out per million with cached input at $0.26, GLM-5.3-Flash costs $0.15 in and $0.50 out, and some older Flash models are free. The GLM Coding Plan starts at $18 a month and plugs into Claude Code through an Anthropic compatible endpoint. Modal sells serverless GPUs with per-second billing, no model catalog and a free Starter plan with $30 of credits every month.
Z.ai wins for anyone who wants GLM tokens now, especially for budget agentic coding. Modal comes in when control matters. Because GLM-5 ships under MIT with no license limits, a team can fine-tune it and serve the checkpoint on Modal. That also keeps traffic off Z.ai's servers, which sit mostly in China and add 100 to 200ms from the US or Europe. The trade is operational: you write the serving code, manage cold starts and pay 3x list for non-preemptible runs, plus 1.15–1.75x to pin a region.
What Modal and Z.ai do
Modal
Modal is serverless compute with GPUs attached. A developer decorates a Python function with the hardware it needs, such as gpu="H100", and Modal builds the container, schedules it, autoscales it and scales it back to zero. Billing runs per second with no minimum increment, from $0.59 an hour for a T4 to $3.95 for an H100 at list. Containers can hold up to 8 GPUs across T4 through B300.
Example models: none hosted by default; teams deploy their own, such as open LLMs on vLLM or Whisper
Full Modal profileZ.ai
Z.AI is the international brand of Chinese lab Zhipu AI, maker of the GLM models. Its current flagship, GLM-5.3, shipped August 17, 2026 at $1.40 in and $4.40 out per million tokens, with cached input at $0.26. Its weights came out August 28 under a custom GLM-5.3 License that requires a security review for hosts with more than $10B in yearly revenue. GLM-5.3-Flash, a 320B multimodal model with 18B active, costs $0.15 in and $0.50 out, and several older Flash models are priced at zero, a real free tier instead of trial credits. GLM-5, released in February 2026, is a 744B mixture-of-experts model under an MIT license, and at launch it ranked first among open-weight models on the Artificial Analysis index with a record-low hallucination score.
Example models: GLM-5.3, GLM-5.3-Flash
Full Z.ai profileShould you choose Modal or Z.ai?
Modal
Choose Modal for
- Serving a fine-tuned GLM checkpoint under your control.
- Keeping inference outside China-hosted servers.
- Spiky custom GPU jobs with per-second billing.
Z.ai
Choose Z.ai for
- Budget agentic coding in Claude Code on an $18 plan.
- A real free tier on older Flash models.
- Cheap GLM tokens with no infrastructure work.
Modal vs Z.ai at a glance
| Attribute | Modal | Z.ai |
|---|---|---|
| Model access | Bring your own weights | Open weights (GLM-5.3 License; MIT on Flash and older) |
| Flagship models | None hosted | GLM-5.3, GLM-5.3-Flash |
| Speed | ~1s container boot | ~80 tok/s on GLM-5.3 |
| Price | Per second; H100 $3.95/hr list | $1.40 in, $4.40 out (GLM-5.3); free Flash tier |
| Customization | Run any training code | Open weights; GLM-5.3 License adds review for large hosts |
| Deployment | Serverless GPU containers | API, GLM Coding Plan |
| Long context | Depends on the model you deploy | 1M (GLM-5.3) |
Frequently asked questions
What is the difference between Modal and Z.ai?
Z.ai sells open-weight GLM models and an $18 coding plan. Modal rents per-second GPUs for whatever model you bring. A ready API versus a compute platform.
When should I choose Modal over Z.ai?
Serving a fine-tuned GLM checkpoint under your control; Keeping inference outside China-hosted servers; Spiky custom GPU jobs with per-second billing.
When should I choose Z.ai over Modal?
Budget agentic coding in Claude Code on an $18 plan; A real free tier on older Flash models; Cheap GLM tokens with no infrastructure work.
Is Modal or Z.ai cheaper?
Modal: Per second; H100 $3.95/hr list. Z.ai: $1.40 in, $4.40 out (GLM-5.3); free Flash tier. The cheaper choice depends on the model and workload.
Which has more context, Modal or Z.ai?
Modal: Depends on the model you deploy. Z.ai: 1M (GLM-5.3).
Related comparisons
Running long-horizon agents?
If your agents run past 200K tokens, compare both against Subconscious. Our inference stack treats a long-horizon trace as the primary workload, so speed, cost, and accuracy hold up deep into the trace.