Gemini 1.5 Flash vs Llama 3.1 405B
Head-to-head specifications
| Metric | Gemini 1.5 Flash | Llama 3.1 405B | Difference |
|---|---|---|---|
| MMLU (general capability) | 78.9% | 88.6% | -9.7% |
| Context window | 1M tokens | 128K tokens | — |
| Price (input / output per 1M) | $0.075 / $0.3 | Open weights | — |
| Access | Proprietary API | Open weights | — |
- Llama 3.1 405B leads general capability (MMLU 88.6% vs 78.9%).
- Gemini 1.5 Flash offers the larger context window, useful for long documents and codebases.
Verdict: Gemini 1.5 Flash or Llama 3.1 405B?
Gemini 1.5 Flash advantages
- Context window (+87%)
Llama 3.1 405B advantages
- General capability (+11%)
Which should you choose?
- Choose the Gemini 1.5 Flash if you work with long documents or large codebases.
- Choose the Llama 3.1 405B if you need the strongest reasoning and accuracy.
Value for money
Llama 3.1 405B is open-weight and can be self-hosted, which can dramatically lower cost at scale versus a per-token API.
Gemini 1.5 Flash vs Llama 3.1 405B: which should you choose?
Gemini 1.5 Flash — Google large language model (2024) with a 1M-token context window and an MMLU score of 78.9%.
Llama 3.1 405B — Meta large language model (2024) with a 128K-token context window and an MMLU score of 88.6%, released with open weights.
Gemini 1.5 Flash vs Llama 3.1 405B: Llama 3.1 405B scores higher on the MMLU benchmark. Llama 3.1 405B leads general capability (MMLU 88.6% vs 78.9%). Gemini 1.5 Flash offers the larger context window, useful for long documents and codebases.
Capability and reasoning
On MMLU — a 57-subject benchmark of general knowledge and reasoning — the Llama 3.1 405B scores 88.6% versus 78.9%. MMLU is a useful proxy for raw knowledge but does not capture instruction-following, coding, tool use, latency or safety, so treat it as one signal among several.
Context window
The Gemini 1.5 Flash handles up to 1 million tokens per request, which sets how much documentation, transcript or code it can reason over at once — decisive for retrieval-augmented and long-document workflows.
Pricing and access
Gemini 1.5 Flash is proprietary api and Llama 3.1 405B is open weights. Proprietary models bill per token via API; open-weight models can be self-hosted, trading per-call cost for infrastructure you manage. For production, weigh throughput, rate limits and data-residency needs alongside headline price.
The verdict
Both are credible choices in the ai model comparison space; the specification table above lays out every metric so you can weigh the trade-offs that matter to you. Pick the one whose strengths line up with how you will actually use it.
Frequently asked questions
Is the Gemini 1.5 Flash better than the Llama 3.1 405B?
These two are closely matched — the right pick comes down to which specific strengths you value and the price you actually pay. Llama 3.1 405B leads general capability (MMLU 88.6% vs 78.9%).
What is the main difference between the Gemini 1.5 Flash and the Llama 3.1 405B?
Llama 3.1 405B leads general capability (MMLU 88.6% vs 78.9%). Gemini 1.5 Flash offers the larger context window, useful for long documents and codebases.
Which is better value?
Llama 3.1 405B is open-weight and can be self-hosted, which can dramatically lower cost at scale versus a per-token API.
Which should I choose?
Choose the Gemini 1.5 Flash if you work with long documents or large codebases. Choose the Llama 3.1 405B if you need the strongest reasoning and accuracy.
Methodology
Large language models are compared on the MMLU benchmark (a widely-cited 57-subject test of general knowledge and reasoning, reported as a percentage), maximum context window, and published API pricing per million input and output tokens. Open-weight models can also be self-hosted. Benchmarks capture only part of real-world quality, which also depends on tool use, latency, safety and task fit.