GPT-5.5

OpenAI🇺🇸 United States
active
Context window1000K tokens
Input / 1M tokens$5
Output / 1M tokens$30

Version History

5.5major

First retrained base model since GPT-4.5, co-designed with NVIDIA GB200/GB300 systems. Significant improvements in agentic benchmarks, particularly Terminal-Bench (82.7%) and long-context retrieval (74.0% on MRCR v2).

Benchmark Scores

Full leaderboard →
1476.0 elo
Arena Elo
93.2%
GPQA
9.3%
Hallucination (Summarization)
91.2%
Hallucination Rate
92.0 tokens_per_sec
Speed (tok/s)

Coverage