Comparison · Z.ai and xAI
Grok 4.5 vs GLM 5.3 Prime
Listed API prices of Grok 4.5 and GLM 5.3 Prime turned into the cost of the same three standard tasks and what each provider’s API documentation says about features that break on a switch. Output quality, speed and answer length are not compared.
Calculated impact cost per task and per month
For an L2 task (deep analysis over a 50,000-token document, 3 steps), Grok 4.5 costs $0.336 and GLM 5.3 Prime $0.472 at the prices listed in the United States on , so Grok 4.5 is 28.8 % less than GLM 5.3 Prime, counting visible output only, without cache discounts or hidden reasoning.
| Task | Grok 4.5, per task | GLM 5.3 Prime, per task | Grok 4.5, per month | GLM 5.3 Prime, per month | Grok 4.5 vs GLM 5.3 Prime, per task |
|---|---|---|---|---|---|
| L1Micro-task (classification or strict JSON extraction) | $0.0042per L1 task | $0.0060per L1 task | $61.32per month | $87.02per month | −29.5 % |
| L2Deep analysis over a 50,000-token document | $0.336per L2 task | $0.472per L2 task | $4,905.60per month | $6,885.36per month | −28.8 % |
| L3Agentic coding loop, 15 steps | $2.69per L3 task | $3.76per L3 task | $39,201.00per month | $54,933.96per month | −28.6 % |
Calculated Per month: 20 tasks an hour around the clock, 730 hours.
Prices USD per 1M tokens
| Price | Grok 4.5 | GLM 5.3 Prime |
|---|---|---|
| Input, per 1M tokens | $2.00 | $2.80 |
| Output, per 1M tokens | $6.00 | $8.80 |
| Price from | OpenRouter · source page (data) Published | OpenRouter · source page (data) Published |
| Read | · the United States | · the United States |
| Context window | 500,000 tokens | 1,000,000 tokens |
What breaks when you switch Published provider documentation
Moving from xAI to Z.ai, 2 of the 5 features may not carry over, by each provider’s documentation:
- Strict JSON schemas — xAI: yes; Z.ai: partly. Code that parses answers without checks starts failing where a provider promises only valid JSON, not your schema.
- Parallel tool calls — xAI: yes; Z.ai: not stated. An agent built around several calls per turn gets one call per turn: more round trips, more input tokens, slower runs.
Moving from Z.ai to xAI: every feature that Z.ai’s documentation lists as supported is also listed as supported by xAI.
| Feature of the API | xAI | Z.ai |
|---|---|---|
| Strict JSON schemas | Yes | Partly |
| Parallel tool calls | Yes | Not stated |
| Streamed tool arguments | No | Partly |
| Reasoning with tools | Yes | Yes |
| Cache covers tool definitions | Not stated | Not stated |
What each provider’s own API documentation says, read ; “not stated” is not the same as “no”. Quotes and sources: what breaks when you switch AI APIs.