Term
GPT Sol
GPT-5.6 Sol is OpenAIs flagship from July 2026 — the top model of a new solar-system family (Sol, Terra, Luna) focused on coding, science and cybersecurity.
GPT Sol — explained in more detail
GPT-5.6 Sol is the top-tier model of OpenAIs GPT-5.6 family. It arrived on June 26, 2026 as a limited preview and moved to general availability on July 9, 2026. With the release OpenAI introduced a solar-system naming scheme: Sol as the flagship, Terra as a balanced everyday model at half the price and Luna as the cheapest, fastest tier. Sol targets the most demanding tasks in coding, science and cybersecurity and ships with OpenAIs most extensive safety stack to date.
Key facts
- Release: June 26, 2026 (preview), July 9, 2026 (general availability); proprietary access via the OpenAI API and Amazon Bedrock.
- Pricing: $5 per 1M input tokens, $30 per 1M output tokens; the compute-intensive Sol Ultra variant uses the same rate card.
- Ultra mode: a compute-intensive setting with greater reasoning depth.
- Pricing update: On August 21, 2026 OpenAI cut Sols API and credit pricing by more than 20 percent for three months.
Example / Practical use
On the coding benchmark Terminal-Bench 2.1 Sol Ultra reaches 91.9 percent and the base variant 88.8 percent — ahead of Claude Mythos 5 and GPT-5.5 per OpenAI. In practice Sol is meant for tasks where maximum model quality outweighs cost and latency: heavy software-engineering runs, scientific analysis and safety-critical workflows. For everyday and high-volume tasks OpenAI points to the cheaper siblings Terra ($2.50/$15) and Luna ($1/$6).
Delimitation
Within the GPT-5.6 family Sol is the most expensive and most capable tier; Terra covers everyday production at half the price, Luna targets latency-critical bulk work. Against the previous generation GPT-5.5, Sol brings measurable gains on coding and scientific benchmarks. Its direct competitor in the same class is Anthropics Claude Mythos 5.