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API price comparison · checked Oct 23, 2026
Claude Opus 5.5 vs GPT-6 Astra: API price
Short answerClaude Opus 5.5 is the cheaper one: 1,000 chatbot replies cost $14.00 against $35.00 on GPT-6 Astra, so GPT-6 Astra costs 2.50x as much. Across our 6 workloads Claude Opus 5.5 is cheaper on 6 and GPT-6 Astra on 0. Standard prices: Claude Opus 5.5 $4 / $20, GPT-6 Astra $10 / $50 per 1M input / output tokens, checked Oct 23, 2026.
Cost of the same work
| Workload (1,000 requests) | Claude Opus 5.5 | GPT-6 Astra | Ratio |
|---|---|---|---|
| Chatbot replya 1,500-token prompt (1,000 of it a fixed system prompt) and a 400-token answer | $14.00 | $35.00 | 0.40x |
| Answer from your docs (RAG)6,000 tokens of retrieved context plus the question, a 500-token answer | $34.00 | $85.00 | 0.40x |
| Summarize a long documenta 20,000-token document in, an 800-token summary out | $96.00 | $240 | 0.40x |
| Coding agent step40,000 tokens of repo context and history (30,000 of it repeated from the last step), 2,000 out | $200 | $500 | 0.40x |
| Batch extraction2,000 tokens per record in, 300 tokens of JSON out, sent through the batch API where there is one | $7.00 | $17.50 | 0.40x |
| Long-document Q&Aa 150,000-token contract or codebase in one prompt, a 1,000-token answer | $620 | $1,550 | 0.40x |
Side by side
| Price | Claude Opus 5.5 | GPT-6 Astra |
|---|---|---|
| Input / 1M | $4 | $10 |
| Output / 1M | $20 | $50 |
| Cache read / 1M | $0.2 | $1 |
| Batch input / output | $2 / $10 | $5 / $25 |
| Long-prompt tier | none listed | over 272,000 |
| Provider | Anthropic | OpenAI |
| Status | listed | listed |
When each one is cheaper
- Claude Opus 5.5 is cheaper or equal on both input and output, so it costs less on every workload at standard prices.
- With caching on a coding-agent step (30,000 of 40,000 input tokens cached): Claude Opus 5.5 $86.00 vs GPT-6 Astra $230 per 1,000 steps (0.37x).
- This page compares price only. Which model answers better for your task is a separate question: test both on your own prompts.
Each model in full
Sources
- Anthropic API pricing: https://platform.claude.com/docs/en/about-claude/pricing, checked Oct 23, 2026.
- OpenAI API pricing: https://developers.openai.com/api/docs/pricing, checked Oct 23, 2026.