Model decision surface
Compare AI models
Start with GPT-5.5 Pro and GPT-6 Astra, or choose any two current ranked language models. Compare capability evidence, price, context, provider availability, and weight access without pretending one field decides every use case.
Current public data
GPT-5.5 Pro vs GPT-6 Astra
Live dataset updated 9/9/2026, 8:46:14 PM UTC
Open 1200×630 evidence receipt| Field | GPT-5.5 Pro OpenAI | GPT-6 Astra OpenAI |
|---|---|---|
| ModelCap position | #49 | #1 |
| Index score | 59.1 | 93.7 |
| Evidence | Measuredpublisher-corpus-prior over 182 held-out anchors (61%); 1 specialist-board observation at 2.1% support (40%); shrunk 14.6 toward the measured corpus | Measured4 public benchmark observations across 4 boards |
| Input / 1M | $30.00 | $10.00 |
| Output / 1M | $180 | $50.00 |
| Pricing status | fresh | fresh |
| Context | 1M | 1M |
| Providers | 1 | 2 |
| Weight access | API only | API only |
Decision facts
- GPT-5.5 Pro is #49; GPT-6 Astra is #1 on the same current language board.
- Index scores are 59.1 for GPT-5.5 Pro and 93.7 for GPT-6 Astra. Their published uncertainty intervals overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.
- Both positions use Measured evidence.
- Listed output price per 1M tokens is $180.00 for GPT-5.5 Pro and $50.00 for GPT-6 Astra. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $150.00 for GPT-5.5 Pro versus $45.00 for GPT-6 Astra. GPT-6 Astra costs 70.0% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.
- Published context is 1,050,000 tokens for GPT-5.5 Pro and 1,050,000 for GPT-6 Astra.
- ModelCap currently lists 1 providers for GPT-5.5 Pro and 2 for GPT-6 Astra.
These are separate published fields, not a synthetic winner. ModelCap does not collapse price, access, context, and capability evidence into a hidden recommendation score.
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Each comparison page is a permanent, shareable URL with the same live figures as this tool: ModelCap Index position, API pricing, context window, provider count, weight access and every shared benchmark board.