OpenAI
GPT-5.5 Pro
GPT-5.5 with extended parallel compute — 6× the price for the hardest problems.
API onlytextimagefileREL 2026-04-24
Compare this model →Verified 2026-06-12
Overview
GPT-5.5 Pro runs the same base model with much larger test-time compute budgets, trading cost and latency for accuracy on the very hardest tasks. At $30/$180 per 1M tokens it costs roughly 6× standard GPT-5.5 and is best reserved for one-shot, high-stakes questions.
Benchmark scores
Methodology →Intelligencen/a
Codingn/a
Reasoningn/a
Mathn/a
Sources and verification
- Catalogue and pricing: OpenRouter model record · checked 2026-06-12
Strengths and weaknesses
Strengths
- Highest-accuracy OpenAI tier
- Extended reasoning budgets
Trade-offs
- $30/$180 per 1M — extreme pricing
- High latency
- Overkill for routine work
Reach for this model when
One-off critical answers: research questions, hard proofs, high-stakes review.
Run something like it locally
No local equivalent at this capability tier.