GPT-5.5 Pro: benchmark results

OpenAI's higher-compute GPT-5.5 variant for demanding reasoning and general tasks. Provider: OpenAI. Released 2026-04-23. Access: API.

Unified ELO 1773 ± 1, rank #9 of 1392 rated models, from 39 benchmark results.

Strongest benchmark results

BenchmarkScoreMetricPercentile
BenchGecko Score99.9Composite Score100
GeneBench33.2Mean pass rate (self-reported)100
OpenAI GPT-5.5 Launch - BrowseComp90.1Score (%)100
OpenAI GPT-5.5 Launch - GeneBench33.2Score (%)100
OpenAI GPT-5.5 Launch - Investment Banking Modeling Tasks88.6Score (%)100
OpenAI GPT-5.5 System Card - Biochemistry Knowledge Improvement39.26reward@4 (%)100
OpenAI GPT-5.5 System Card - DNA Sequence Design for TF Binding16.5pass@1 (%)100
OpenAI GPT-5.5 System Card - Tacit Knowledge and Troubleshooting81.67Score (%)100
OpenAI GPT-5.6 System Card - DNA Sequence Design for TF Binding16.5pass@1 (%)100
OpenAI GPT-Rosalind-5.5 System Card - Biorisk Knowledge81.67cons@32 (%)100
OpenAI GPT-Rosalind-5.5 System Card - DNA Sequence Design for TF Binding16.5pass@1 (%)100
OpenAI GPT-Rosalind-5.5 System Card - Multi-select Virology Troubleshooting55.34pass@1 (%)100

Interactive version: theaggregate.ai/model?slug=gpt-5-5-pro · How It Works · Data refreshed daily, snapshot 2026-09-05.