GPT-6 Astra vs GPT-5.6 Sol
A current, source-checked comparison of GPT-6 Astra and GPT-5.6 Sol, focused on context, pricing and practical model selection.
Astra is OpenAI’s higher-end choice for the hardest end-to-end work. Sol keeps the same 1.05M context and 128K output limits at 40% of Astra’s standard input/output token price, making it the stronger cost-first default when Astra-level capability is unnecessary.
Specs side by side
| Area | GPT-6 Astra | GPT-5.6 Sol |
|---|---|---|
| Standard input / 1M | $10 | $4 |
| Cached input / 1M | $1 | $0.40 |
| Standard output / 1M | $50 | $20 |
| Context window | 1,050,000 | 1,050,000 |
| Max output | 128,000 | 128,000 |
| Knowledge cutoff | Apr 30, 2026 | Feb 16, 2026 |
| Positioning | Hardest end-to-end work | Complex professional work |
How to choose
Do not pick a model from a benchmark headline alone. Compare the models on the exact workload you care about: same prompts, same tool permissions, similar reasoning settings, repeated runs, recorded date and measured cost. We will add independent tests here as they are completed.
What this comparison does not claim
Model capabilities move quickly and vendor benchmarks are not interchangeable. This page avoids declaring a universal “winner” until matched-task tests are available.
Frequently asked questions
Is GPT-6 Astra better than GPT-5.6 Sol?
There is no single answer for every workload. Astra is a premium flagship model; the better choice depends on task quality, latency, context needs, tool support and cost.
Are the prices on this page current?
They are reviewed against first-party vendor documentation on September 5, 2026. Always verify vendor pricing before production deployment.
Primary sources
Specifications and prices can change. We prefer first-party documentation and record the date each page was reviewed.