GPT-5.5
Last updated: April 22, 2026
Specs
| Vendor | OpenAI |
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| Released | March 18, 2026 |
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| Context window | 600K tokens |
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| Input | $12 / M tokens |
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| Output | $48 / M tokens |
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Benchmarks
| mmlu | 93 |
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| gpqa | 68.7 |
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| humanEval | 94.2 |
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| arenaElo | 1432 |
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| sweBench | 66 |
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| sweBenchPro | 58.6 |
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| liveCodeBench | 76 |
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| aiderPolyglot | 77 |
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| terminalBench | 46 |
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| mmluPro | 86 |
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| hle | 26 |
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| aime | 92 |
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| math500 | 96.5 |
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| mmmu | 79 |
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Strengths
- Highest Arena Elo on the OpenAI roadmap: edges Opus 4.7
- Native multimodal including realtime voice and video
- Faster than o3/o4 at frontier quality
Weaknesses
- Premium pricing: $12/M input
- Still catching up to Claude on long-horizon agent reliability
- Rate limits on tier 5 accounts are restrictive at launch
Best for
- Multimodal flagship agents
- Voice + vision + text assistants
- Teams on OpenAI infra wanting the best single model
Compare with other AI models