Open models
This reference covers the API-only flagship capability tier in a model family whose tiers advance on independent cadences. It keeps sibling pricing changes and hosted availability separate from capability claims.
GPT-5.6 Sol is the vendor reference for gpt-5.6-sol, as of Aug 12, 2026. Context window: 1,050,000, as of Aug 12, 2026. RunInfra has not measured this model; every figure below belongs to its named source, cited and dated.
| Group | Fact | Source-cited display value | Source and date |
|---|---|---|---|
| Identity | API model id | gpt-5.6-sol | developers.openai.comRetrieved |
| Identity | Series launch | We're launching the GPT-5.6 family of models for general availability following our limited preview: our new flagship, Sol, alongside Terra, a balanced model for everyday work, and Luna, our most cost-efficient model. | openai.comRetrieved |
| Identity | Series launch publication date | July 9, 2026 | openai.comRetrieved |
| Identity | Series naming system | In this new naming system introduced with GPT-5.6, the number identifies a model's generation, while Sol, Terra, and Luna identify durable capability tiers that can advance on their own cadence. | openai.comRetrieved |
| Identity | Preview publication date | June 26, 2026 | openai.comRetrieved |
| Identity | Vendor positioning | GPT-5.6 Sol sets a new standard for both intelligence and efficiency, achieving state-of-the-art results across coding, knowledge work, cybersecurity, and science while outperforming previous and competing frontier models with fewer tokens and at lower estimated cost. | openai.comRetrieved |
| Architecture | - | Architecture facts not published | - |
| Context | Context window | 1,050,000 | developers.openai.comRetrieved |
| Context | Maximum input | 922,000 tokens | developers.openai.comRetrieved |
| Context | Maximum output | 128,000 tokens | developers.openai.comRetrieved |
| Context | Knowledge cutoff | February 16, 2026 | developers.openai.comRetrieved |
| Modalities | Input and output | text and image input; text output | developers.openai.comRetrieved |
| Modalities | Reasoning effort | none, low, medium (default), high, xhigh, and max | developers.openai.comRetrieved |
| Modalities | Maximum reasoning effort | max gives GPT-5.6 even more time than xhigh to reason and explore alternatives, run checks, and revise its approach. | openai.comRetrieved |
| Modalities | Ultra mode | ultra goes further by coordinating four agents in parallel by default, trading higher token use for stronger results and faster time-to-result on demanding tasks. | openai.comRetrieved |
| License | - | License facts not published | - |
| Pricing | OpenAI API price: OpenAI standard input | $5.00 per 1M tokens | developers.openai.comRetrieved |
| Pricing | OpenAI API price: OpenAI standard cached input | $0.50 per 1M tokens | developers.openai.comRetrieved |
| Pricing | OpenAI API price: OpenAI standard cache write | $6.25 per 1M tokens | developers.openai.comRetrieved |
| Pricing | OpenAI API price: OpenAI standard output | $30.00 per 1M tokens | developers.openai.comRetrieved |
| Pricing | OpenAI API price: OpenAI long-context input | $10.00 per 1M tokens | developers.openai.comRetrieved |
| Pricing | OpenAI API price: OpenAI long-context cached input | $1.00 per 1M tokens | developers.openai.comRetrieved |
| Pricing | OpenAI API price: OpenAI long-context cache write | $12.50 per 1M tokens | developers.openai.comRetrieved |
| Pricing | OpenAI API price: OpenAI long-context output | $45.00 per 1M tokens | developers.openai.comRetrieved |
| Pricing | OpenAI API price: Long-context threshold | Prompts with >272K input tokens are priced at 2x input and 1.5x output | developers.openai.comRetrieved |
| Pricing | OpenAI API price: Cache economics | cache writes are billed at 1.25x the model's uncached input rate, while cache reads continue to receive the 90% cached-input discount. | openai.comRetrieved |
| Pricing | OpenAI API price: Sibling price cut | Update on July 30, 2026: OpenAI reduced the price of GPT-5.6 Luna by 80% and GPT-5.6 Terra by 20%. | openai.comRetrieved |
| Pricing | OpenAI API price: OpenRouter listing | $5.00/M input tokens and $30.00/M output tokens; listed July 9, 2026 | openrouter.aiRetrieved |
| Availability | Launch availability | GPT-5.6 is available starting today across ChatGPT, Codex, and the OpenAI API. | openai.comRetrieved |
| Availability | Tier rate limits | Tier 5: 15,000 RPM and 40,000,000 TPM | developers.openai.comRetrieved |
| Availability | Sol Pro | Pro and Enterprise users can also select GPT-5.6 Sol Pro for the highest-quality results on complex tasks. | openai.comRetrieved |
"We're launching the GPT-5.6 family of models for general availability following our limited preview: our new flagship, Sol, alongside Terra, a balanced model for everyday work, and Luna, our most cost-efficient model."
openai.comRetrieved
"ultra goes further by coordinating four agents in parallel by default, trading higher token use for stronger results and faster time-to-result on demanding tasks."
openai.comRetrieved
These results are vendor-claimed, not independently measured by RunInfra.
| Benchmark | Vendor-claimed value | Source and date |
|---|---|---|
| Agents' Last Exam | 52.7% | openai.comRetrieved |
| Artificial Analysis Intelligence Index v4.1 | 58.9 | openai.comRetrieved |
| Artificial Analysis Coding Agent Index v1.1 | 80 | openai.comRetrieved |
| SWE-Bench Pro | 64.6% | openai.comRetrieved |
| DeepSWE v1.1 | 72.7% | openai.comRetrieved |
| Terminal-Bench 2.1 | 88.8% | openai.comRetrieved |
| BrowseComp | 90.4% | openai.comRetrieved |
| OSWorld 2.0 | 62.6% | openai.comRetrieved |
| GPQA Diamond | 94.6% | openai.comRetrieved |
| Capture-the-Flag | 96.7% | openai.comRetrieved |
| FrontierMath Tiers 1-3 | 89% | openai.comRetrieved |
| MMMU Pro, no tools | 83% | openai.comRetrieved |
Listed rows have a cited upstream support signal. They are not RunInfra measurements.
No open-engine serving signal applies to this model. It is served only through the vendor's own API.
RunInfra has not measured this model yet. When measurement is published, the record will state throughput, latency, memory, quality, serving conditions, and reproducible evidence.
As of Aug 12, 2026, API model id: gpt-5.6-sol.
OpenAI API price: As of Aug 12, 2026, OpenAI standard input: $5.00 per 1M tokens. OpenAI standard cached input: $0.50 per 1M tokens. OpenAI standard cache write: $6.25 per 1M tokens. OpenAI standard output: $30.00 per 1M tokens. OpenAI long-context input: $10.00 per 1M tokens. OpenAI long-context cached input: $1.00 per 1M tokens. OpenAI long-context cache write: $12.50 per 1M tokens. OpenAI long-context output: $45.00 per 1M tokens. Long-context threshold: Prompts with >272K input tokens are priced at 2x input and 1.5x output. Cache economics: cache writes are billed at 1.25x the model's uncached input rate, while cache reads continue to receive the 90% cached-input discount. Sibling price cut: Update on July 30, 2026: OpenAI reduced the price of GPT-5.6 Luna by 80% and GPT-5.6 Terra by 20%. OpenRouter listing: $5.00/M input tokens and $30.00/M output tokens; listed July 9, 2026.
No, API only. As of Aug 12, 2026, Launch availability: GPT-5.6 is available starting today across ChatGPT, Codex, and the OpenAI API.
Use a workspace API key and pay for input, cached input, and output tokens.
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