All modelsOpenAI
GPT-5.5
Best terminal/CLI autonomy and dense academic reasoning. Effort variants up to max.
FrontierProprietary400K contextReleased Apr 2026textvisionaudio-inaudio-outcode
API price · per 1M tokens
$10/$30
input / output
≈ $15.00/M blended
Benchmarks
Bar shows this model's score; tick shows the best score across all tracked models for context.
SWE-bench VerifiedReal GitHub issues, human-verified patches. The standard coding-agent benchmark.
88.7/ best 90.1SWE-bench Pro2,294 harder real-world GitHub issues. Where the frontier separates now.
58.6/ best 69.2Terminal-Bench 2.xAgentic command-line workflows — planning, iteration, tool coordination.
82.7/ best 84.0GPQA DiamondGoogle-proof graduate-level science Q&A. General reasoning proxy.
93.6/ best 94.4MMLU-ProMulti-task language understanding across 120+ academic subjects.
92.4/ best 93.0HumanEval+Functional code generation from docstrings.
95.2/ best 96.0MATH-500Competition-style math problems.
97.1/ best 97.8Humanity's Last ExamHardest reasoning benchmark (with tools). ~50% = near frontier.
52.2/ best 57.9AIME 2025American Invitational Mathematics Examination.
95.5/ best 96.5OSWorldReal computer-use tasks across desktop apps.
78.7/ best 83.4