Gemini 3.1 Flash-Lite vs GLM-5.1
Gemini 3.1 Flash-Lite and GLM-5.1 are both current production-tier models. Gemini 3.1 Flash-Lite is meaningfully cheaper at $0.25 / $1.5 per 1M. Gemini 3.1 Flash-Lite has a 1M context window — about 5× the 200k of GLM-5.1. Gemini 3.1 Flash-Lite leads on long-context retrieval. GLM-5.1 leads on coding, reasoning, general knowledge.
Specs side by side
| Metric | Google Gemini 3.1 Flash-Lite | Z.ai GLM-5.1 |
|---|---|---|
| Input price (per 1M) | $0.25 | $1 |
| Output price (per 1M) | $1.5 | $3.2 |
| Context window | 1M tokens | 200k tokens |
| Speed tier | ultra | balanced |
| Open weights | No | Yes |
| EU region | Yes | No |
| Free tier | Google AI Studio | bigmodel.cn |
| Prompt caching | No | No |
| Vision input | Yes | No |
| Extended thinking | No | Yes |
When to choose each
Choose Gemini 3.1 Flash-Lite if…
- Cost is a priority ($0.25 / $1.5 per 1M vs $1 / $3.2 per 1M)
- You need 1M context (5× more than GLM-5.1)
- Low latency matters (ultra vs balanced)
- EU data residency 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 3.1 Flash-Lite leads on
- Long-context retrieval
GLM-5.1 leads on
- Coding
- Reasoning
- General knowledge
- Instruction following
- Multilingual
- Tool use
FAQ — Gemini 3.1 Flash-Lite vs GLM-5.1
Gemini 3.1 Flash-Lite vs GLM-5.1 — which is better?
Gemini 3.1 Flash-Lite and GLM-5.1 are both current production-tier models. Gemini 3.1 Flash-Lite is meaningfully cheaper at $0.25 / $1.5 per 1M. Gemini 3.1 Flash-Lite has a 1M context window — about 5× the 200k of GLM-5.1. Gemini 3.1 Flash-Lite leads on long-context retrieval. GLM-5.1 leads on coding, reasoning, general knowledge. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.
How does Gemini 3.1 Flash-Lite pricing compare to GLM-5.1?
Gemini 3.1 Flash-Lite costs $0.25 / $1.5 per 1M vs GLM-5.1 at $1 / $3.2 per 1M. Gemini 3.1 Flash-Lite is cheaper on output tokens by roughly 113%.
Does Gemini 3.1 Flash-Lite or GLM-5.1 have the bigger context window?
Gemini 3.1 Flash-Lite 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 3.1 Flash-Lite or GLM-5.1?
Gemini 3.1 Flash-Lite: yes — Reduced daily quota; most generous free tier of any frontier lab. GLM-5.1: yes — Free tier with monthly token allowance.
Which is better for coding — Gemini 3.1 Flash-Lite or GLM-5.1?
GLM-5.1 leads on coding benchmarks (Gemini 3.1 Flash-Lite: 72/100, GLM-5.1: 93/100). For production coding agents also weigh tool-use performance — Gemini 3.1 Flash-Lite scores 76, GLM-5.1 scores 86.