Gemini 3.8 Flash vs GPT-5.6 Sol

Side-by-side pricing per provider, context window, benchmark scores and speed, all on one OpenAI-compatible API.

Metric
Gemini 3.8 FlashGooglegoogle/gemini-3.8-flash
GPT-5.6 SolOpenAIopenai/gpt-5.6-sol
Creator
Google
OpenAI
Released
Sep 2, 2026
Jul 9, 2026
Context window
1.05M
1.05M (best)
Max output
66K
128K (best)
Input / 1MLowest provider price
$0.75 (best)
$4.00
Output / 1MLowest provider price
$3.75 (best)
$20.00
Providers
2 (best)
1
IntelligenceArtificial Analysis index
40.9
42.3 (best)
CodingArtificial Analysis index
76.3
77.2 (best)
LatencyMedian time to first token
—
5.7s
ThroughputMedian tokens per second
—
<1 t/s
Accepts
Text, Image, Audio, Video, Files
Text, Image
Produces
Text
Text
Tool calling
Yes
Yes
Structured output
No
Yes
Reasoning
No
Yes

Gemini 3.8 Flash vs GPT-5.6 Sol: summary

Gemini 3.8 Flash and GPT-5.6 Sol are both available through FastRouter's OpenAI-compatible API, so switching between them is a change of model id, not a new integration.

Gemini 3.8 Flash, from Google, has a 1,048,576-token context window, costs from $0.75/1M input and $3.75/1M output tokens across 2 providers and scores 40.9 on the Artificial Analysis Intelligence Index.

GPT-5.6 Sol, from OpenAI, has a 1,050,000-token context window, costs $4.00/1M input and $20.00/1M output tokens and scores 42.3 on the Artificial Analysis Intelligence Index.

Gemini 3.8 Flash is the cheapest on input, 5.3× cheaper than the next model, GPT-5.6 Sol has the largest context window, GPT-5.6 Sol scores highest for intelligence and GPT-5.6 Sol leads on coding.

Switch with one line

client = OpenAI(base_url="https://api.fastrouter.ai/api/v1", api_key="<FASTROUTER_API_KEY>") client.chat.completions.create(model="google/gemini-3.8-flash", messages=[...]) # or client.chat.completions.create(model="openai/gpt-5.6-sol", messages=[...])
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Benchmark scores sourced from ArtificialAnalysis