Claude Opus 5.5 vs GPT-6 Astra
A plain comparison: what they do, what they cost and which to pick for your task.
In short
The strongest models for hard work. Opus 5.5 is two and a half times cheaper and better at code and writing; pick GPT-6 Astra for the hardest reasoning and research.
Claude Opus 5.5 is cheaper: an answer costs 2.5 times less than with GPT-6 Astra.
Side by side
| Claude Opus 5.5 | GPT-6 Astra | |
|---|---|---|
| Maker | Anthropic, USA | OpenAI, USA |
| Type | flagship | the strongest |
| Good for | Claude’s flagship for hard writing, code and analysis. Half the price of Fable and handles most difficult tasks. | The smartest ChatGPT model. For hard problems, research and difficult maths. |
| Official, $ per 1M | $4 / $20 | $10 / $50 |
| Freepay rate | ×2 / ×10 | ×5 / ×25 |
| Maker’s subscription | Claude Pro costs about $20 a month. | ChatGPT Plus costs $20 a month. |
Prices: your text / answer. The “Freepay rate” shows how many balance tokens a model spends per token of its own; Claude Sonnet 5.5 is ×1.
Which to pick for the task
| Task | Better |
|---|---|
| Hard code | Claude Opus 5.5 |
| Writing | Claude Opus 5.5 |
| Hard reasoning | GPT-6 Astra |
| Price | Claude Opus 5.5 |
The best way to choose is to ask both models the same question. On Freepay you do it in one chat, switching the model in the input field.
About Claude Opus 5.5
Claude’s flagship for hard writing, code and analysis. Half the price of Fable and handles most difficult tasks. Claude is made by Anthropic, a US company. People pick it for natural writing, strong code and the way it handles long documents. More about Claude Opus 5.5.
About GPT-6 Astra
The smartest ChatGPT model. For hard problems, research and difficult maths. GPT models are made by OpenAI and power ChatGPT, the best-known AI chat. It answers any question, does maths, explains and helps with study. More about GPT-6 Astra.
Frequently asked questions
Which is better, Claude Opus 5.5 or GPT-6 Astra?
The strongest models for hard work. Opus 5.5 is two and a half times cheaper and better at code and writing; pick GPT-6 Astra for the hardest reasoning and research.
Which is cheaper, Claude Opus 5.5 or GPT-6 Astra?
Claude Opus 5.5 is cheaper: an answer costs 2.5 times less than with GPT-6 Astra. Official prices per 1M tokens: Claude Opus 5.5 $4 / $20, GPT-6 Astra $10 / $50. On Freepay both are 10x cheaper.
Can I use Claude Opus 5.5 and GPT-6 Astra in one place?
Yes. On Freepay both models are in one chat, you switch them in the input field, and the balance is shared.
Do I need two subscriptions for Claude Opus 5.5 and GPT-6 Astra?
No. On claude.ai you need an account and a phone number, the free plan has tight message limits, and Claude Pro is a monthly subscription. ChatGPT needs an account, the free plan limits the best models, and ChatGPT Plus is a monthly subscription. On Freepay one key covers both, with no subscription.