GPT-5.6 is OpenAI’s current frontier model family. In the API, the gpt-5.6 alias routes to GPT-5.6 Sol: the highest-capability tier, aimed at complex coding, agentic workflows, research and professional analysis.
It is a commercial, API-first model rather than software you can run on your own hardware. Its 1.05 million-token context window makes it a serious option for large codebases and long document sets, though even with promotional rates it is not the economical choice for routine high-volume jobs.
At a glance
| Fact | Detail |
| --- | --- |
| Provider | OpenAI |
| Type | Commercial / proprietary |
| Best for | Coding, agents, research, document analysis |
| Context window | 1,050,000 tokens |
| Maximum output | 128,000 tokens |
| API available | Yes |
| Local use | No |
| Last checked | 31 August 2026 |
Our verdict
GPT-5.6 Sol is worth using when the work is genuinely difficult: engineering tasks, tool-using agents, research synthesis and large document or repository analysis. Promotional short-context pricing of $4 / $20 per million input/output tokens, available at least through 21 November 2026, improves the case — but cheaper GPT-5.6 tiers still win for routine jobs.
| Area | Score |
| --- | --- |
| Overall | ★★★★☆ |
| Coding | ★★★★★ |
| Agents | ★★★★★ |
| Research | ★★★★☆ |
| Budget | ★★★☆☆ |
Pricing
Promotional standard API prices per million tokens, short context, listed by OpenAI through at least 21 November 2026:
| Meter | Price |
| --- | --- |
| Input | $4.00 / million tokens |
| Cached input | $0.40 / million tokens |
| Cache writes | $5.00 / million tokens |
| Output | $20.00 / million tokens |
Long-context columns on the same official table are $8.00 input, $0.80 cached input and $30.00 output per million tokens. Batch and Fast mode differ from these standard rates.
Best for
- Complex coding, agents and professional analysis
- Large codebases and long document sets
- Work where better results justify frontier spend
Avoid when
- You need local inference or open weights
- The job is routine classification, simple writing or bulk automation
- Luna or Terra can do the work at lower cost
What changed
- 31 August 2026: Official pricing re-checked. Short-context Sol rates are $4 / $0.40 / $20 per million tokens, promotional through at least 21 November 2026.
- 21 August 2026: OpenAI dropped GPT-5.6 Sol API pricing by over 20%.
- 16 July 2026: Profile created; pricing and context checked against OpenAI documentation.
- 9 July 2026: OpenAI introduced the GPT-5.6 family, with Sol as its frontier tier. The
gpt-5.6API alias routes to Sol.
Related news
- OpenAI Unveils GPT-5.6 With Sol, Terra, and Luna — AI Gets a Pricing Ladder
- White House Asks OpenAI to Limit GPT-5.6 to Government-Approved Partners
- OpenAI’s GPT-5.6 push is really a pricing war for enterprise AI
