For coding agents, Gemini 3.1 Pro costs 12x as much as Gemini 3.1 Flash Lite per request ($0.095 vs $0.0082 on our measured traffic), because Gemini 3.1 Pro lists at $2 input, $0.20 cached input and $12 output per million tokens against $0.25, $0.025 and $1.50 for Gemini 3.1 Flash Lite, and Gemini 3.1 Pro charges more for prompts over 200K tokens.
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| Cost at list price | Flash Lite | Gemini 3.1 Pro |
|---|---|---|
| Prompt under 100K tokens50% of requests, 87% of input cached | $0.0040 | $0.032 |
| Prompt of 100K to 272K39% of requests, 88% of input cached | $0.0099 | $0.11 |
| Prompt over 272K tokens11% of requests, 86% of input cached | $0.022 | $0.34 |
| Average request | $0.0082 | $0.095 |
| 100 requests | $0.82 | $9.48 |
| Median session16 requests; a session ends after 10 idle minutes | $0.11 | $0.93 |
| A month of regular usemedian of 20 users active on 5+ days | $12.53 | $135 |
Each logged request priced at the listed rates above for its own token counts, including cache reads and any higher rate for long prompts. Average output: 698 tokens per request.
| Artificial Analysis | Flash Lite | Gemini 3.1 Pro |
|---|---|---|
| Intelligence Index10 evaluations, 0 to 100 | 16 | 30 |
| Terminal-Bench 4.0agentic coding in a terminal | 0.5% | 4.0% |
| Output speedmedian | 365 tokens/s | 144 tokens/s |
| Time to first answer tokenincludes thinking time | 5.0 s | 23 s |
Source: Artificial Analysis (artificialanalysis.ai). Measured variants: Gemini 3.1 Flash-Lite, speed on Google; Gemini 3.1 Pro Preview, speed on Google. Fetched October 13, 2026. Artificial Analysis runs Terminal-Bench 4.0 in its own setup, so its scores differ from the tbench.ai leaderboard.
The gap widens on long prompts: under 100K tokens Gemini 3.1 Pro costs 8.0x as much per request, over 272K 16x. The price is OpenRouter's listed rate on October 13, 2026, which can be a third-party host's; Google's own API may charge differently. Gemini 3.1 Pro scores clearly higher on the benchmarks above, so it may finish hard tasks in fewer steps.
Pick a winner in each dimension. You can change your vote any time.
Correctness and depth of what it produces
Tool calls, instruction-following, and multi-step tasks
Tokens per second and time-to-first-token
How much capability you get per dollar
Consistent results: fewer refusals, loops and format breaks
Setting it up? Gemini 3.1 Pro: model ID, providers and agent config
The agent matters as much as the model. Compare AI agents →
Current Claude, GPT, Gemini and open models run on Standard Compute