Gemini 3 Flash vs GLM-5.1
Gemini 3 Flash and GLM-5.1 are both current production-tier models. Gemini 3 Flash has a 1M context window — about 5× the 200k of GLM-5.1. Gemini 3 Flash leads on long-context retrieval. GLM-5.1 leads on coding, reasoning.
Specs side by side
| Metric | Google Gemini 3 Flash | Z.ai GLM-5.1 |
|---|---|---|
| Input price (per 1M) | $0.5 | $1 |
| Output price (per 1M) | $3 | $3.2 |
| Context window | 1M tokens | 200k tokens |
| Speed tier | fast | balanced |
| Open weights | No | Yes |
| EU region | Yes | No |
| Free tier | Google AI Studio | bigmodel.cn |
| Prompt caching | Yes | No |
| Vision input | Yes | No |
| Extended thinking | Yes | Yes |
When to choose each
Choose Gemini 3 Flash if…
- You need 1M context (5× more than GLM-5.1)
- EU data residency is required
- HIPAA eligibility is required
- You need image input / vision
- Long-context retrieval is central to your workload
Choose GLM-5.1 if…
- You need open weights for self-hosting or fine-tuning
- Coding is central to your workload
- Reasoning is central to your workload
Benchmark delta
Gemini 3 Flash leads on
- Long-context retrieval
GLM-5.1 leads on
- Coding
- Reasoning
FAQ — Gemini 3 Flash vs GLM-5.1
Gemini 3 Flash vs GLM-5.1 — which is better?
Gemini 3 Flash and GLM-5.1 are both current production-tier models. Gemini 3 Flash has a 1M context window — about 5× the 200k of GLM-5.1. Gemini 3 Flash leads on long-context retrieval. GLM-5.1 leads on coding, reasoning. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.
How does Gemini 3 Flash pricing compare to GLM-5.1?
Gemini 3 Flash costs $0.50 / $3 per 1M vs GLM-5.1 at $1 / $3.2 per 1M. Gemini 3 Flash is cheaper on output tokens by roughly 7%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.
Does Gemini 3 Flash or GLM-5.1 have the bigger context window?
Gemini 3 Flash has a 1M-token context window — 5× the 200k context of GLM-5.1. Enough for entire codebases, books, or multi-document RAG.
Is there a free tier for Gemini 3 Flash or GLM-5.1?
Gemini 3 Flash: yes — Reduced daily quota; rate-limited for prototyping. GLM-5.1: yes — Free tier with monthly token allowance.
Which is better for coding — Gemini 3 Flash or GLM-5.1?
GLM-5.1 leads on coding benchmarks (Gemini 3 Flash: 84/100, GLM-5.1: 93/100). For production coding agents also weigh tool-use performance — Gemini 3 Flash scores 85, GLM-5.1 scores 86.