GPT-5.5 vs Gemini 2.5 Pro Experimental

1. Strongest Agentic Coding Model

• State-of-the-art on Terminal-Bench 2.0 (82.7%), Expert-SWE (73.1%), and SWE-Bench Pro (58.6%), outperforming GPT-5.4 on complex coding tasks.
• Holds context across large systems, reasons through ambiguous failures, and carries changes through surrounding codebases with fewer tokens.

2. Higher Intelligence at GPT-5.4 Latency

• Co-designed, trained, and served on NVIDIA GB200/GB300 NVL72 systems to match GPT-5.4 per-token latency while performing at a significantly higher level.
• Uses fewer tokens to complete the same tasks, making it more efficient as well as more capable.

3. Powerful for Knowledge Work & Computer Use

• Scores 84.9% on GDPval (44 occupations) and 78.7% on OSWorld-Verified for autonomous computer operation.
• Excels at generating documents, spreadsheets, and reports; naturally moves across finding information, using tools, and checking output.

4. Scientific Research Co-Scientist

• Leading performance on GeneBench, BixBench, and FrontierMath; helped discover a new proof about Ramsey numbers verified in Lean.
• Strong enough to meaningfully accelerate progress at the frontiers of biomedical and mathematical research.

1. State-of-the-art reasoning performance

• #1 on LMArena human preference leaderboard.
• Excels at advanced reasoning benchmarks like GPQA and AIME 2025.
• Achieves 18.8% on Humanity's Last Exam (no tools), representing frontier human-level reasoning.

2. New “thinking model” architecture

• Built with explicit reasoning steps internally before responding.
• Handles complex, multi-stage logic with higher accuracy and fewer hallucinations.

3. Elite science and mathematics capabilities

• Leads in math and science tasks across industry benchmarks.
• High performance without costly inference tricks like majority voting.

4. Exceptional coding abilities

• Major leap over Gemini 2.0 in coding performance.
• 63.8% on SWE-Bench Verified with custom agent setup.
• Strong at code transformation, debugging, and building agentic apps.
• Capable of generating full applications (e.g., a playable video game) from a single-line prompt.

5. Massive multimodal context

• Ships with a 1,000,000 token window (2M coming soon).
• Handles entire documents, datasets, video sequences, audio files, and large codebases.
• Maintains strong performance even at extreme context lengths.

6. Native multimodality across all inputs

• Understands and reasons over text, images, audio, video, and code.
• Designed for real-world, multi-source problem-solving and agent workflows.

7. Consistent high-quality outputs

• Improved post-training results in more accurate, coherent, and stylistically strong responses.
• Higher reliability across complex workloads.

8. Early availability for developers

• Available today in Google AI Studio for experimentation.
• Coming soon to Vertex AI with higher rate limits and production-ready access.