Claude Opus 5 vs GPT-6 Astra: pricing and benchmarks
Claude Opus 5 is 50% cheaper on input tokens ($5.00 vs $10.00 per 1M). Claude Opus 5 is 50% cheaper on output tokens ($25.00 vs $50.00 per 1M). On our document Q&A workload (50,000 questions a month), Claude Opus 5 costs $2,750 a month versus $5,500 for GPT-6 Astra, 50% less. Roughly tied. Claude Opus 5 scores 162.3 and GPT-6 Astra scores 166.3 on the Epoch Capabilities Index, and their confidence intervals overlap.
Prices verified September 14, 2026.
Which should you choose?
Roughly tied. Claude Opus 5 scores 162.3 and GPT-6 Astra scores 166.3 on the Epoch Capabilities Index, and their confidence intervals overlap.
About even on DeepSWE: 73.6% for Claude Opus 5 and 74.1% for GPT-6 Astra.
GPT-6 Astra scores 93.7% on FrontierMath (Tiers 1–3) vs 85.6% for Claude Opus 5.
Claude Opus 5 costs $10.00 per 1M tokens (3:1 input-to-output mix) vs $20.00 for GPT-6 Astra, 50% less.
Claude Opus 5 delivers statistically similar overall capability for 50% less.
Pricing and specs
| Claude Opus 5 | GPT-6 Astra | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| API model ID | claude-opus-5 | gpt-6-astra |
| Input / 1M tokens | $5.00 | $10.00 |
| Cached input / 1M tokens | $0.50 | $1.00 |
| Output / 1M tokens | $25.00 | $50.00 |
| Long-context rates | — | $20.00 in / $75.00 out on long-context requests |
| Context window | 1M tokens | 1.05M tokens |
| Max output | 128K tokens | 128K tokens |
| Batch discount | 50% off | 50% off |
Benchmarks
| Claude Opus 5 | GPT-6 Astra | |
|---|---|---|
| Epoch Capabilities Index | 162.3 | 166.3 |
| GPQA Diamond· Science reasoning | 91.8% | 94.4% |
| FrontierMath (Tiers 1–3)· Advanced math | 85.6% | 93.7% |
| SimpleQA Verified· Factual accuracy | 59.9% | 75.6% |
| ARC-AGI-2· Abstract reasoning | 90.4% | 95.0% |
| DeepSWE· Coding | 73.6% | 74.1% |
| APEX-Agents· Agentic work | 43.5% | 46.7% |
Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks
Monthly cost for real workloads
| Workload | Claude Opus 5 | GPT-6 Astra | Difference |
|---|---|---|---|
Support chatbot 100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each. | $1,750 | $3,500 | Claude Opus 5 50% cheaper |
Document Q&A (RAG) 50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each. | $2,750 | $5,500 | Claude Opus 5 50% cheaper |
Coding agent 10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens. | $1,240 | $2,480 | Claude Opus 5 50% cheaper |
Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.
Claude Opus 5 vs GPT-6 Astra cost calculator
- $2,750/mo$0.06 / request
- GPT-6 AstraOpenAI$5,500/mo$0.11 / request
Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.
Claude Opus 5 pricing notes
Anthropic’s model for complex agentic coding and enterprise work.
- Cache writes cost $6.25 (5-minute cache) or $10 (1-hour cache) per 1M tokens.
- Uses Anthropic’s newer tokenizer, which produces roughly 30% more tokens for the same text.
- US-only inference (inference_geo: "us") costs 1.1x.
GPT-6 Astra pricing notes
OpenAI’s most capable model, built for the hardest end-to-end reasoning and coding work.
- Cache writes are billed at $12.50 per 1M tokens.
- Fast mode costs 2x the standard rate; Flex costs half.
- Regional (data residency) endpoints add a 10% uplift.
Frequently asked questions
- Is Claude Opus 5 cheaper than GPT-6 Astra?
- Claude Opus 5 is 50% cheaper on input tokens ($5.00 vs $10.00 per 1M). Claude Opus 5 is 50% cheaper on output tokens ($25.00 vs $50.00 per 1M). On our document Q&A workload (50,000 questions a month), Claude Opus 5 costs $2,750 a month versus $5,500 for GPT-6 Astra, 50% less.
- Which is more capable, Claude Opus 5 or GPT-6 Astra?
- Roughly tied. Claude Opus 5 scores 162.3 and GPT-6 Astra scores 166.3 on the Epoch Capabilities Index, and their confidence intervals overlap.
- How much does Claude Opus 5 cost per 1M tokens?
- Claude Opus 5 costs $5.00 per 1M input tokens and $25.00 per 1M output tokens, and $0.50 per 1M cached input tokens on Anthropic’s standard tier.
- How much does GPT-6 Astra cost per 1M tokens?
- GPT-6 Astra costs $10.00 per 1M input tokens and $50.00 per 1M output tokens, and $1.00 per 1M cached input tokens on OpenAI’s standard tier.
- Which has the larger context window, Claude Opus 5 or GPT-6 Astra?
- GPT-6 Astra has the larger context window: 1.05M tokens versus 1M for Claude Opus 5.