Plain-English Summary
OpenAI’s highest-capability GPT-5.6 model for difficult professional, analytical, and coding work.
GPT-5.6 Sol
OpenAI’s highest-capability GPT-5.6 model for difficult professional, analytical, and coding work.
GPT-5.6
Reasoning LLM
GA
Open weights: No
API: Yes
Technical Notes
Proprietary multimodal reasoning model with a 1.05M-token context window, 128K output limit, tool use, and structured outputs.
Best For
Complex coding, deep analysis, long documents, autonomous agents
Watch Out For
Highest cost in the GPT-5.6 family; may be slower than smaller tiers.
Model Specs
- Maker
- OpenAI
- Country
- USA
- Family
- GPT-5.6
- Type
- Reasoning LLM
- Release date
- 2026-07-09
- Date confidence
- Exact
- Status
- GA
- Context window
- 1,050,000 tokens
- Max output
- 128,000
- Parameters
- Not disclosed
- Active parameters
- Not disclosed
- Architecture
- Proprietary multimodal transformer
- Reasoning
- Yes — configurable
- Tool calling
- Yes
- Structured output
- Yes
- API available
- Yes
- Open weights
- No
- Self-hostable
- No
- License
- Proprietary
- Inputs
- Text, image
- Outputs
- Text
- Approx. price
- $5 input / $30 output per 1M tokens
- How to access
- Provider website or API
- Model / API ID
- gpt-5.6-sol
- Knowledge cutoff
- 2026-02-16
- Fine-tuning
- Prompting, tools, retrieval; provider-managed
- Completeness
- 90 %
- Verified
- Jul 18, 2026
- Snapshot date
- Jul 18, 2026
- Source
- Official source