Claude Opus 5.5 vs GPT-6 Astra
Claude Opus 5.5 and GPT-6 Astra are the two flagship models most often shortlisted for hard, long-running work. Claude Opus 5.5 lists at $4 / $20 per 1M tokens and GPT-6 Astra at $10 / $50.
Our verdict
Start with Claude Opus 5.5. Our example job costs $8 on Claude Opus 5.5 against $20 on GPT-6 Astra at list price, and Claude Opus 5.5 scores higher on the independent Artificial Analysis index (58 against 53) and on LiveBench overall (83.2 against 82.2), both from the 1 Oct 2026 captures. Pay GPT-6 Astra rates only for work that is a long chain of clicks, forms and file handling: OpenAI reports 72.6% on the OSWorld 2.0 computer-use benchmark (its own figure), and that is where GPT-6 Astra is genuinely ahead. Neither score measures your own job, so run both on one real task and compare the bills.
Benchmarks measure test tasks, not your business. Run a real job through both models before you commit.
Side by side
| Claude Opus 5.5 | GPT-6 Astra | |
|---|---|---|
| Lab | Anthropic | OpenAI |
| List price per 1M tokens (input / output) | $4 / $20 | $10 / $50 |
| Scheduled price | - | - |
| Price notes | Cache reads $0.20 per 1M; fast mode $8 / $40. | Prompts over 272K input tokens bill the whole request at 2x input and 1.5x output. |
| Example job at list price | $8 | $20 |
| Context window | 1,000,000 tokens | 922,000 tokens |
| Released | ||
| Open weights | No | No |
| Artificial Analysis Intelligence Index | 58 (Oct 1, 2026 capture) | 53 (Oct 1, 2026 capture) |
| LiveBench overall | 83.2 | 82.2 |
1M tokens in and 200K tokens out. List price only: models write different amounts, so a finished job can cost more or less. (1,000,000 / 200,000)
Common questions
Is GPT-6 Astra better than Claude Opus 5.5?
On the independent Artificial Analysis index Opus 5.5 scores 58 and Astra 53, and on LiveBench Opus leads 83.2 to 82.2 (1 Oct 2026 captures). Astra's clearest lead is computer use, where OpenAI reports 72.6% on OSWorld 2.0, its own figure.
How much more does GPT-6 Astra cost than Claude Opus 5.5?
Astra lists at $10 in and $50 out per 1M tokens against $4 and $20 for Opus 5.5, so our example job (1M tokens in, 200K out) costs $20 against $8. Astra prompts over 272K input tokens bill the whole request at double input and 1.5 times output.
Which should a small business use?
Opus 5.5 for most hard work, because it costs less and scores higher. Keep Astra for tasks that operate a computer end to end. For routine drafting and sorting, neither is the right purchase: see the cheaper models on the AI models page.
Sources
More model comparisons
All model comparisonsSee every model on the AI model tracker
Not sure which model your business needs?
Dapols picks the models and tools for your budget and shows the bill before you spend.