Decision summary
- Hardest flagship agents -> GPT-6 Astra
- Cheaper GPT-6 coding lane -> GPT-6 Sol
- High-volume leftovers -> GPT-6 Luna
- Existing GPT-5.6 Sol pin -> see the Sol upgrade page before assuming Astra
- No published Astra-vs-Sol benchmark -> do not invent a winner
OpenAI flagship tier comparison
Frontier comparisonGPT-6 Astra vs GPT-6 Sol
GPT-6 Astra remains OpenAI's flagship.
Featured · Updated today · Last verified: September 2026
Choose GPT-6 Astra when
The hardest OpenAI coding, computer-use, research, and document work.
Choose GPT-6 Sol when
Complex coding and agentic workflows when Astra's list price is too high.
- Hardest flagship agents: GPT-6 Astra
- Cheaper GPT-6 coding lane: GPT-6 Sol
- High-volume leftovers: GPT-6 Luna
Decision axes: Best for · Access and platforms · Context window · Input and output
Reasoning
Astra documents low through max. Sol documents none through max, default medium.
Coding
Astra is the flagship. Sol is the cheaper complex-coding lane. No score table is published.
Multimodal
Text and image in, text out.
Speed
Fast mode is 2× on both.
Enterprise
Astra is off by default for Enterprise and marked Critical cyber. Do not copy that status onto Sol.
Curated matrix for GPT-6 Astra vs GPT-6 Sol — confirm live limits and pricing on each vendor’s official pages.
How they compare
Criterion-by-criterion notes from the catalog—not a ranking. Validate on your own gold set.
| Criterion | GPT-6 Astra | GPT-6 Sol |
|---|---|---|
| Best for | The hardest OpenAI coding, computer-use, research, and document work. | Complex coding and agentic workflows when Astra's list price is too high. |
| Access and platforms | gpt-6-astra. Paid ChatGPT rollout and Bedrock. Free API tier unsupported. Enterprise off by default. | gpt-6-sol in the API, plus ChatGPT Work and Codex on paid, Business, Enterprise, and Edu plans. |
| Context window | 1,050,000 / 128K. Knowledge cutoff April 30, 2026. | 1,050,000 / 128K. Knowledge cutoff April 20, 2026. |
| Input and output | Text and image in; text out. | Text and image in; text out. |
| Reasoning control | low through max, including xhigh. | none through max. Default medium. none is required for Chat Completions function calling. |
| Coding and agents | Flagship Responses API surface, including computer use and hosted shell. | Documented Responses tools match the current Sol card, including computer use. Quality versus Astra is not scored on that card. |
| Cost posture | $10 / $1 cached / $12.50 cache write / $50 output per 1M, with long-context multipliers above 272K. | $2 / $0.20 cached / $2.50 cache write / $10 output per 1M. Same 272K long-context rule. |
| Operational risk | Preparedness Critical cyber and workspace gates. Do not assume Sol inherits that status. | Teams may under-buy Astra or over-buy Sol. Replay one hard repo task before you lock the route. |
Key insights
Concrete technical or product signals.
- Standard short-context list price is 5× higher on Astra for both input ($10 vs $2) and output ($50 vs $10).
- Context length matches. Knowledge cutoff does not: Astra April 30, 2026; Sol April 20, 2026.
- Missing head-to-head scores are omitted on purpose.
Use cases
Where this shines in production.
- Splitting Astra and Sol traffic
- Repricing an OpenAI coding agent
- Deciding the paid ChatGPT Work default
Limitations & trade-offs
What to watch for.
- Not Astra vs Claude.
- Not proof that Sol equals Astra at one-fifth the price.
- Critical-cyber language on Astra does not automatically transfer to Sol.
Watch-outs
Who should pass, and what to validate before rollout.
- Do not assume Sol equals Astra at one-fifth the price.
- Do not assume Sol inherits Astra's Critical-cyber status.
- Do not use either model as a high-volume default if Luna clears the task.
Final recommendation
What to do after reading the table.
Keep Astra on the hardest slice and trial Sol on the next slice. Standardize only after the replay.
FAQ
Is GPT-6 Astra better than GPT-6 Sol?
Keep Astra on the hardest slice and trial Sol on the next slice. Standardize only after the replay.
Which is better for coding: GPT-6 Astra or GPT-6 Sol?
GPT-6 Astra: Flagship Responses API surface, including computer use and hosted shell. GPT-6 Sol: Documented Responses tools match the current Sol card, including computer use. Quality versus Astra is not scored on that card. The catalog does not declare a winner on coding and agents.
Which is cheaper: GPT-6 Astra or GPT-6 Sol?
Listed unit prices: GPT-6 Astra $10 / $1 cached / $12.50 cache write / $50 output per 1M, with long-context multipliers above 272K; GPT-6 Sol $2 / $0.20 cached / $2.50 cache write / $10 output per 1M. Same 272K long-context rule. A lower listed unit price is not the same as a lower total workload cost—tokens, session minutes, caching, introductory rates, and add-on modes can reverse the ranking. Confirm live rates on each vendor’s official page.
Can I use both GPT-6 Astra and GPT-6 Sol?
Yes. Many teams keep both and route by constraint. Use GPT-6 Astra for The hardest OpenAI coding, computer-use, research, and document work, and GPT-6 Sol for Complex coding and agentic workflows when Astra's list price is too high. Confirm vendor terms before mixing them in one production workflow.