GPT-5.6 Sol
OpenAI's flagship tier and the current state of the art on agentic coding benchmarks. Reasoning effort is tunable from none through max, and an `ultra` setting coordinates parallel subagents across workstreams. Sol reaches near-Fable-5 intelligence while spending markedly fewer output tokens, which is why its cost per finished task lands well below its sticker price.
Pricing checked against provider documentation on . How we verify
gpt-5.6-sol reasoning Input
$4.00
/ 1M tokens
Output
$20.00
/ 1M tokens
Context
1.05M
1,048,576 tokens
Max output
128K
tokens per request
Pricing caveat: Promotional pricing (down from $5/$30) held at least through 2026-11-21. Prompts above 272K input tokens bill at higher rates; 'fast' processing is 2x.
What it costs in practice
A workload of 10M input and 2M output tokens per month — roughly a moderately busy production assistant — runs $80.00/month on GPT-5.6 Sol. Routing that same volume through the batch API brings it to $40.00. The next cheaper option, Kimi K3 , would cost $60.00.
Where GPT-5.6 Sol fits
- Long-running autonomous coding agents
- Large-scale refactors and migrations
- Agentic browsing and computer use
- Scientific and financial analysis
Published benchmarks
| Benchmark | Score |
|---|---|
| Artificial Analysis Coding Agent Index | 80 |
| Agents' Last Exam | 53.6 |
| BrowseComp | 92.2% |
| OSWorld 2.0 | 62.6% |
Scores are self-reported by providers or drawn from independent indices. Treat them as directional and validate on your own evals.
Specifications
- API model ID
- gpt-5.6-sol
- Provider
- OpenAI
- Model family
- GPT-5.6
- Released
- July 2026
- Knowledge cutoff
- February 2026
- Context window
- 1,048,576 tokens
- Max output
- 128,000 tokens
- Native reasoning
- Yes
- Relative latency
- high
- Input modalities
- text, image, audio
- Output modalities
- text
- Open weights
- No
- Cached input
- $0.40 / 1M tokens
- Batch discount
- 50%
Frequently asked
How much does GPT-5.6 Sol cost?
GPT-5.6 Sol costs $4.00 per million input tokens and $20.00 per million output tokens, with cached input at $0.40. Batch processing is 50% cheaper.
What is GPT-5.6 Sol's context window?
GPT-5.6 Sol accepts up to 1,048,576 tokens of context and can generate up to 128,000 output tokens per request.
Is GPT-5.6 Sol a reasoning model?
Yes. GPT-5.6 Sol performs native chain-of-thought before answering. Those thinking tokens are billed at the output rate, so budget above the sticker price.
What is GPT-5.6 Sol best for?
Frontier coding and long-horizon agents. OpenAI's flagship tier and the current state of the art on agentic coding benchmarks. Reasoning effort is tunable from none through max, and an `ultra` setting coordinates parallel subagents across workstreams. Sol reaches near-Fable-5 intelligence while spending markedly fewer output tokens, which is why its cost per finished task lands well below its sticker price.