GLM-5.1 vs Grok 4.3
GLM-5.1 and Grok 4.3 are both current production-tier models. Grok 4.3 is meaningfully cheaper at $1.25 / $2.5 per 1M. GLM-5.1 leads on multilingual. Grok 4.3 leads on instruction following, tool use.
Specs side by side
| Metric | Z.ai GLM-5.1 | xAI Grok 4.3 |
|---|---|---|
| Input price (per 1M) | $1.4 | $1.25 |
| Output price (per 1M) | $4.4 | $2.5 |
| Context window | 200k tokens | 256k tokens |
| Speed tier | balanced | balanced |
| Open weights | Yes | No |
| EU region | No | No |
| Free tier | bigmodel.cn | No |
| Prompt caching | No | Yes |
| Vision input | No | Yes |
| Extended thinking | Yes | Yes |
When to choose each
Choose GLM-5.1 if…
- You need open weights for self-hosting or fine-tuning
- You want a free tier for prototyping
- Multilingual is central to your workload
Choose Grok 4.3 if…
- Cost is a priority ($1.25 / $2.5 per 1M vs $1.4 / $4.4 per 1M)
- You need image input / vision
- Instruction following is central to your workload
- Tool use is central to your workload
Benchmark delta
GLM-5.1 leads on
- Multilingual
Grok 4.3 leads on
- Instruction following
- Tool use
FAQ — GLM-5.1 vs Grok 4.3
GLM-5.1 vs Grok 4.3 — which is better?
GLM-5.1 and Grok 4.3 are both current production-tier models. Grok 4.3 is meaningfully cheaper at $1.25 / $2.5 per 1M. GLM-5.1 leads on multilingual. Grok 4.3 leads on instruction following, tool use. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.
How does GLM-5.1 pricing compare to Grok 4.3?
GLM-5.1 costs $1.4 / $4.4 per 1M vs Grok 4.3 at $1.25 / $2.5 per 1M. Grok 4.3 is cheaper on output tokens by roughly 76%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.
Does GLM-5.1 or Grok 4.3 have the bigger context window?
Grok 4.3 has a 256k-token context window — 1× the 200k context of GLM-5.1. Enough for long reports and multi-document analysis.
Is there a free tier for GLM-5.1 or Grok 4.3?
GLM-5.1: yes — Free tier with monthly token allowance. Grok 4.3: no — X Premium / SuperGrok includes Grok web chat; API is paid.
Which is better for coding — GLM-5.1 or Grok 4.3?
GLM-5.1 leads on coding benchmarks (GLM-5.1: 93/100, Grok 4.3: 91/100). For production coding agents also weigh tool-use performance — GLM-5.1 scores 86, Grok 4.3 scores 90.