GPT-6 Astra and Claude Opus 5 are the current flagships from OpenAI and Anthropic — the models you reach for when the task is genuinely hard. Here's how they stack up on the things that decide a bill: price, context, and fit.
Key takeaways
- Both are top-tier reasoning models with large context windows.
- Opus 5 is cheaper per token; Astra prices higher, especially on output.
- Match the model to the task — neither is the right default for cheap, high-volume work.
- On a gateway you can run both and switch per request.
Price & context, side by side
| Model | Input /1M (list) | Output /1M (list) | Context |
|---|---|---|---|
| GPT-6 Astra | $20.00 | $75.00 | ~1M |
| Claude Opus 5 | $5.00 | $25.00 | 1M |
These are provider list prices at time of writing and will change. Always check the live figure on the Astra and Opus 5 pages before you budget.
What each is best at
GPT-6 Astra
The broadest frontier model — strong multimodal input, a deep tooling ecosystem, and excellent general reasoning. Reach for it on complex agentic chains and mixed-media tasks.
Claude Opus 5
Exceptional at long-context reasoning and disciplined instruction-following, at a noticeably lower token price. Reach for it on long-document analysis and careful, auditable work.
A quick cost example
A request with a 10,000-token prompt and a 2,000-token response:
At scale that gap compounds — which is exactly why you don't want to hardcode one flagship for every call.
The verdict
Use Opus 5 as your default heavy model for its price-to-reasoning ratio; reach for Astra when you need its multimodal breadth or ecosystem. Keep both one string apart.
Both run through the withConflux gateway on one key — so this isn't a permanent decision. Trial them on your own prompts and let the results pick. For the wider family view, see OpenAI vs Anthropic.
One key runs both flagships — and every cheaper model under them. Compare the full lineup.