Gemini 3.8 Flash vs GPT-6.1 Sol
Harvey LAB-AA 1.1?
Gemini 3.8 Flashat high0
GPT-6.1 Solat max6.9
| Benchmark | Gemini 3.8 Flash | GPT-6.1 Sol |
|---|---|---|
| Arena Text · creative writing | 1,487 · high | 1,458 · max |
| Harvey LAB-AA 1.1 | 0 · high | 6.9 · max |
| EQ-Bench Longform Creative Writing 1.11 | 76.8 | — |
| EQ-Bench Creative Writing v3 | 1,747.9 | — |
| Lech Mazur Short-Story | 0.1 · high | — |
Specs
| Spec | Gemini 3.8 Flash | GPT-6.1 Sol |
|---|---|---|
| Input, per 1M | !$0.75 | $2 |
| Output, per 1M | !$3.75 | $10 |
| Cost per task? | $0.93 | $0.21 |
| Speed, tok/s | — | 52 |
| Context | 1M | 1.05M |
| Weights | Closed | Closed |
| Released | Sep 2026 | Sep 2026 |
| See images | ✓ | ✓ |
| Read PDFs | ✓ | Partial |
| Hear audio | ✓ | — |
| Watch video | ✓ | — |
| Call tools | ✓ | ✓ |
| Force a tool call | Partial | Partial |
| Return strict JSON | ✓ | ✓ |
| Search the web | ✓ | ✓ |
| Run code | ✓ | ✓ |
| Use a computer | ? | ✓ |
What breaks when you switch
Gemini 3.8 Flash → GPT-6.1 Sol
Remove unsupported parameters›
With reasoning enabled, remove temperature, top_p and top_logprobs, plus Chat Completions logprobs or Responses message.output_text.logprobs includes.
Responses API for tool calling · Chat Completions›
Use Responses for tools; Chat Completions supports this model without tool calling.
No none or minimal reasoning›
The none and minimal reasoning efforts are unsupported; choose low, medium, high, xhigh or max.
More than 272K input tokens›
Prompts above 272K input tokens charge 2× input and cache rates and 1.5× output rates for the entire request.
Cache writes billed at 1.25x›
Cache writes cost 1.25× the uncached input token rate.
Ultrafast prices 6x Standard›
Ultrafast mode costs 6× Standard token prices.
GPT-6.1 Sol → Gemini 3.8 Flash
Context: 1.05M → 1M
Sampling parameters are ignored›
temperature, top_p and top_k are ignored now and will cause HTTP 400 in future generations; remove them from requests.
No minimal thinking level›
The minimal thinking level returns an error; avoid minimal.