GPT-5.5 Pro vs OpenAI o3
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
GPT-5.5 Pro
OpenAI · Apr 2026
The maximum-compute tier of GPT-5.5 for the hardest research, math and engineering problems, at a steep per-token premium.
OpenAI o3
68.9OpenAI · Apr 2025
OpenAI's dedicated 2025 reasoning model that pioneered thinking-with-images and agentic tool use within chain-of-thought.
The verdict
These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. On price the gap is dramatic: OpenAI o3 works out roughly 19x cheaper per blended million tokens. GPT-5.5 Pro also takes 1M of context versus 200K for OpenAI o3.
Specs & pricing
| GPT-5.5 Pro | OpenAI o3 | |
|---|---|---|
| modhub Index | — | 68.9 |
| Input price / 1M | $30 | $2 |
| Output price / 1M | $180 | $8 |
| Context window | 1M | 200K |
| Max output | 128K | 100K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text, image |
| Knowledge cutoff | Jan 2026 | May 2024 |
| Released | Apr 2026 | Apr 2025 |
| Example monthly cost* | $570.00 | $32.00 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, GPT-5.5 Pro or OpenAI o3?
- These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. On price the gap is dramatic: OpenAI o3 works out roughly 19x cheaper per blended million tokens. GPT-5.5 Pro also takes 1M of context versus 200K for OpenAI o3.
- Which is cheaper, GPT-5.5 Pro or OpenAI o3?
- GPT-5.5 Pro costs $30/$180 per million input/output tokens, while OpenAI o3 costs $2/$8. For a typical workload of 10M input and 1.5M output tokens per month, that's $570.00 versus $32.00.
- Which model is better for coding, GPT-5.5 Pro or OpenAI o3?
- We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.