# GPT-6 Astra vs GPT-6 Sol

URL: https://aistack.sh/compare/gpt-6-astra-vs-gpt-6-sol
Last updated: 2026-09-24
Model pages: https://aistack.sh/model/gpt-6-astra, https://aistack.sh/model/gpt-6-sol

## Quick answer

Start with GPT-6 Sol: it is the Codex default, built for complex coding and agentic workflows, and costs $2 / $10 per 1M tokens. Step up to GPT-6 Astra, OpenAI's most capable model, for the hardest end-to-end work, at 5x the price ($10 / $50).

## Specs

| Spec | GPT-6 Astra | GPT-6 Sol |
| --- | --- | --- |
| Released | - | Sep 22, 2026 |
| Status | Available | Rolling out |
| API model ID | gpt-6-astra | gpt-6-sol |
| API price (in / out) | $10 / $50 per 1M tokens | $2 / $10 per 1M tokens |
| Cache read | $1 per 1M tokens | $0.20 per 1M tokens |
| Context window | 1.05M tokens | 1.05M tokens |
| Plans | - | Plus, Pro, Business, Enterprise, Edu |
| Platforms | OpenAI API | OpenAI API |
| Runs in | ChatGPT, Codex | Codex, ChatGPT |

"-" means the value could not be verified on a vendor page.

## FAQ

### What is the price difference between GPT-6 Astra and GPT-6 Sol?

Astra is $10 input and $50 output per 1M tokens; Sol is $2 and $10. Astra costs 5x as much at OpenAI's short-context rates.

### Which one does Codex use by default?

GPT-6 Sol, starting on the Sol Light preset. Astra is available in the Codex CLI, IDE extension and Codex cloud, but you pick it yourself.

### Do they have different context windows?

No. OpenAI lists 1.05M tokens for both.

## Also compared

- [Claude Opus 5.5 vs GPT-6 Astra](https://aistack.sh/compare/claude-opus-5-5-vs-gpt-6-astra)
- [Claude Opus 5.5 vs GPT-6 Sol](https://aistack.sh/compare/claude-opus-5-5-vs-gpt-6-sol)

## Sources

- [OpenAI: ChatGPT and Codex models](https://learn.chatgpt.com/docs/models), read 2026-09-24
- [OpenAI API models](https://developers.openai.com/api/docs/models), read 2026-09-24
- [OpenAI API: GPT-6 Astra](https://developers.openai.com/api/docs/models/gpt-6-astra), read 2026-09-24
- [OpenAI API pricing](https://developers.openai.com/api/docs/pricing), read 2026-09-24
- [OpenAI: ChatGPT Work and Codex changelog](https://learn.chatgpt.com/docs/changelog), read 2026-09-24