GPT-6.1 Sol

GPT-6.1 Sol is an update to GPT-6 Sol that OpenAI says comes close to GPT-6 Astra on coding, computer use and professional work at one-fifth of Astra's standard token prices. Released September 29, 2026, it shares the family's 1.05M-token context window and 128K-token output limit.

By OpenAIReleased September 29, 2026Data checked October 10, 2026

CurrentClosedAdvanced

Specifications

Context window: 1.05Mabout 788,000 words, or 1,580 pages
Max output: 125Ktokens per response
Input price: $2per 1M tokens
Output price: $10per 1M tokens
Cached input: $0.10per 1M tokens
Weights: ClosedProprietary
Parameters: Undisclosed
Input types: Text, Images
Output types: Text
Reasoning mode: Yes
Tool calling: Yes
Released: Sep 29, 2026Current

Standard rates for prompts up to 272K input tokens; a larger prompt costs $4 input, $0.20 cached and $15 output. Batch and Flex 50% off; Fast mode 2x; Ultrafast 6x. Regional processing adds 10%.

What it costs in practice

Workload	Monthly cost at list price
Support chatbot30,000 conversations a month, 2,000 input and 400 output tokens each	$240
Document summaries2,000 documents a month, 12,000 input and 800 output tokens each	$64
Coding agent1,000 tasks a month, 60,000 input and 6,000 output tokens each	$180

Standard rates, no caching or batch discounts. Run your own numbers.

Strengths

$2 input and $10 output per million tokens, with cached input at $0.10
1.05M-token context window
Optional Fast and Ultrafast service tiers for quicker responses

Trade-offs to weigh

Tool calling requires the Responses API; Chat Completions works without tools
No 'none' reasoning setting, unlike GPT-6 Sol and GPT-6 Luna

Where it fits

OpenAI positions GPT-6.1 Sol for:

codingagentsreasoningenterprise

Where you can use it

API
ChatGPT
Codex
OpenRouter

Alternatives to consider

Model	Tier	Context	Input / output per 1M
Claude Sonnet 5.5Anthropic	Advanced	1M	$2 / $10	Compare
Mistral Medium 3.5Mistral AI	Advanced	256K	$1.50 / $7.50	Compare
Muse Spark 1.3Meta	Advanced	1M	$1.25 / $4.25	Compare
Gemini 3.8 FlashGoogle	Advanced	1M	$0.75 / $3.75	Compare

Frequently asked questions

How much does GPT-6.1 Sol cost?

GPT-6.1 Sol lists at $2 per million input tokens and $10 per million output tokens, with cached input at $0.10 (checked October 10, 2026). Standard rates for prompts up to 272K input tokens; a larger prompt costs $4 input, $0.20 cached and $15 output. Batch and Flex 50% off; Fast mode 2x; Ultrafast 6x. Regional processing adds 10%. Confirm current rates on the provider's pricing page before you commit.

What is the context window of GPT-6.1 Sol?

GPT-6.1 Sol accepts up to 1,050,000 tokens of context (about 788,000 words, or 1,580 pages), and it can write up to 125K tokens in a single response. Long prompts cost more and can be slower, so most apps send only what the task needs.

Is GPT-6.1 Sol open source?

No. GPT-6.1 Sol is a proprietary model from OpenAI; its weights aren't published. You can use it through the OpenAI API and through ChatGPT, Codex, OpenRouter.

What is GPT-6.1 Sol best for?

OpenAI positions GPT-6.1 Sol for coding, agents, reasoning, enterprise. It accepts text, images as input, has a reasoning (thinking) mode and supports tool calling. Test it on a sample of your own tasks before you choose it for production.

Sources

Facts checked against these pages on October 10, 2026. Spot an error? Tell us.

Still choosing a model?

Send us your use case and constraints. We'll come back with a shortlist and an evaluation plan you can run on your own data.

Free and vendor-neutral: no model provider pays for placement.
Your details go only to partners you agree to.