Compare AI models

Decision facts

• GPT-5.5 is #13; o3 is #53 on the same current language board.
• Index scores are 82.5 for GPT-5.5 and 66.5 for o3. Their published uncertainty intervals do not overlap, but the aggregate Index does not predict performance on every task; compare the relevant benchmark configurations before choosing.
• Both positions use Measured evidence.
• Listed output price per 1M tokens is $30.00 for GPT-5.5 and $8.00 for o3. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $25.00 for GPT-5.5 versus $8.00 for o3. o3 costs 68.0% 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 and 200,000 for o3.
• ModelCap currently lists 3 providers for GPT-5.5 and 1 for o3.

These are separate published fields, not a synthetic winner. ModelCap does not collapse price, access, context, and capability evidence into a hidden recommendation score.