OpenAI: GPT-5.5 Pro vs OpenAI: gpt-oss-120b
Side-by-side comparison. Updated 2026-06-08.
Verdict
OpenAI: GPT-5.5 Pro wins on higher overall score (9.5 vs 8.2, +1.3).
- Larger context window (1050k vs 131k)
At a Glance
| Attribute | OpenAI: GPT-5.5 Pro | OpenAI: gpt-oss-120b |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Tags | Intelligent Reasoning Coding Agentic Long Context | Open Weight Intelligent |
| Context | 1,050,000 tokens | 131,072 tokens |
| Input price | $30.00/1M | $0.04/1M |
| Output price | $0.18/1M | $0.18/1M |
| Input modalities | File, Image, Text | Text |
| Output modalities | Text | Text |
OpenAI: GPT-5.5 Pro Strengths
- Unmatched deep reasoning for complex high-stakes workloads
- 1M+ token context window with image input support
- Excels at long-horizon agents and multi-step coding
- Precise execution across agentic workflows
OpenAI: gpt-oss-120b Strengths
- First open-weight release from OpenAI (Apache 2.0)
- Efficient 117B MoE architecture (5.1B active params)
- Strong reasoning and agentic capabilities
- Ultra-budget pricing for self-hosted deployment