Documentation-based comparison
Gemini 3.8 Flash versus GPT-6.1 Sol
Compare documented scope and conditions. Unknowns remain unknown; different billing units do not establish a cost winner.
What the evidence answers
A reading of reviewed official documentation for Gemini 3.8 Flash and GPT-6.1 Sol. It is not a hands-on test, a ranking or a recommendation of one product.
Price
- Gemini 3.8 Flash Usage-based API pricing
- GPT-6.1 Sol Usage-based API pricing
These prices use differently defined usage units. Read each with its own unit and conditions; they do not add up to one total or a cheaper product.
Documented for both
- Provider
- Gemini 3.8 Flash Google
- GPT-6.1 Sol OpenAI
- API model identifier
- Gemini 3.8 Flash gemini-3.8-flash
- GPT-6.1 Sol gpt-6.1-sol
- Modalities
- Gemini 3.8 Flash Text, image, video, audio and PDF input; text output
- GPT-6.1 Sol Text and image input; text output
- Context window
- Gemini 3.8 Flash 1,048,576 input tokens (not a shared context-window measurement)
- GPT-6.1 Sol 1,050,000 tokens in the context window
- Maximum output
- Gemini 3.8 Flash 65,536 output tokens
- GPT-6.1 Sol 128,000 output tokens
- Input token rate
- Gemini 3.8 Flash 0.75 USD per million input tokens
- GPT-6.1 Sol 2 USD per million input tokens
- Output token rate
- Gemini 3.8 Flash 3.75 USD per million output tokens, including thinking
- GPT-6.1 Sol 10 USD per million output tokens
- Availability
- Gemini 3.8 Flash Stable model alias; documentation lists a September 2026 update.
- GPT-6.1 Sol Listed for paid API usage tiers; Free tier is not supported.
Limits to check
- Gemini 3.8 Flash The documented input limit is 1,048,576 tokens and output limit is 65,536. The standard paid rates shown here expire after 31 December 2026.
- GPT-6.1 Sol The 1,050,000-token context window and 128,000-token output ceiling are different limits. Long prompts and premium service tiers change token rates.
Not verified yet
Every compared requirement has evidence for at least one.
Not verified means our reviewed sources do not establish it. It does not mean a product lacks the capability or that it costs nothing.
Next steps
| Requirement | Gemini 3.8 Flash | GPT-6.1 Sol |
|---|---|---|
| Pricing | Usage-based API pricing | Usage-based API pricing |
| Who it is for | A Google Gemini model accepting text, images, video, audio and PDFs, with text output. Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | An OpenAI model accepting text and images and producing text. Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| Coverage limits | The documented input limit is 1,048,576 tokens and output limit is 65,536. The standard paid rates shown here expire after 31 December 2026. Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | The 1,050,000-token context window and 128,000-token output ceiling are different limits. Long prompts and premium service tiers change token rates. Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| Provider | Google Provider identity is linked to the separate Google Gemini API entry. Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | OpenAI Provider identity is linked to the separate OpenAI API catalogue entry. Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| API model identifier | gemini-3.8-flash Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | gpt-6.1-sol Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| Modalities | Text, image, video, audio and PDF input; text output Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | Text and image input; text output Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| Context window | 1,048,576 input tokens (not a shared context-window measurement) Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | 1,050,000 tokens in the context window Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| Maximum output | 65,536 output tokens Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | 128,000 output tokens Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| Input token rate | 0.75 USD per million input tokens Gemini 3.8 Flash Standard paid tier through 31 December 2026; USD 1.50 from 1 January 2027. Cache storage, grounding, other service tiers and taxes are separate. Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | 2 USD per million input tokens Standard uncached text input for prompts up to 272K input tokens. Longer prompts: 2x input/cache and 1.5x output for the full request. Fast 2x, Ultrafast 6x; regional processing adds 10% where available. Cache writes, tools and tax are additional scopes. Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| Output token rate | 3.75 USD per million output tokens, including thinking Gemini 3.8 Flash Standard paid tier through 31 December 2026; USD 7.50 from 1 January 2027. Other service tiers, cache storage, grounding and taxes are separate. Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | 10 USD per million output tokens Standard text output for prompts up to 272K input tokens. Above 272K input tokens: 1.5x output rate. Fast, Ultrafast, regional processing, tools and tax can change the total. Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| Availability | Stable model alias; documentation lists a September 2026 update. Documentation status, not an account-specific access guarantee. Verified Oct 18, 2026 · Gemini 3.8 Flash: official API documentation | Listed for paid API usage tiers; Free tier is not supported. Published rate-limit table, not a verification of regional eligibility or access for a particular account. Verified Oct 18, 2026 · GPT-6.1 Sol: official API documentation |
| Coverage note | Official documentation checked on 18 October 2026; no hands-on test. | Official documentation checked on 18 October 2026; no hands-on test. |