OpenAI's GPT-5.5 is here, and it's no potato: narrowly beats Anthropic's Claude Mythos Preview on Terminal-Bench 2.0

2026-04-23 · Source: VentureBeat · Field: Technology & Digital — Artificial Intelligence & Machine Learning, Robotics & Autonomous Systems · Depth: Advanced, medium

Summary

OpenAI has launched GPT-5.5, its latest large language model, which reclaims the lead in generally available LLMs over rivals like Anthropic's Claude Opus 4.7 and Google's Gemini 3.1 Pro. Internally codenamed "Spud," GPT-5.5 is positioned as a fundamental redesign for intelligence interaction with operating systems and professional software, excelling particularly in coding, computer use, and scientific research. It is available in two variants, GPT-5.5 and GPT-5.5 Pro, with the latter offering enhanced precision for high-stakes environments like legal research. While API access is not yet available, the model is accessible to ChatGPT Plus, Pro, Business, and Enterprise subscribers. GPT-5.5 demonstrates significant performance gains, including a 20% increase in token generation speeds due to hardware-software co-design on NVIDIA GB200 and GB300 NVL72 systems, and outperforms its predecessor, GPT-5.4, on benchmarks like Terminal-Bench 2.0 (82.7% accuracy) and Expert-SWE.

Key takeaway

For CTOs and VP of Engineering evaluating LLM adoption, GPT-5.5 represents a significant leap in agentic capabilities, particularly for coding and complex workflows. While API costs are higher, its token efficiency and ability to handle multi-step tasks autonomously could reduce overall operational overhead and accelerate development cycles. You should consider piloting GPT-5.5 for critical software development or scientific research initiatives to assess its impact on productivity and accuracy, especially given its benchmark leads in computer use and economic knowledge work.

Key insights

GPT-5.5 redefines AI agency, excelling in complex, multi-part tasks with less human guidance.

Principles

• Agentic AI reduces granular prompting.
• Hardware-software co-design boosts efficiency.
• Specialized licenses manage cyber risks.

Method

GPT-5.5 utilizes custom heuristic algorithms, written by AI, to partition and balance work across GPU cores on NVIDIA GB200/GB300 NVL72 systems, increasing token generation speeds by over 20%.

In practice

• Use GPT-5.5 for complex coding tasks.
• Employ "Thinking" mode for high-stakes reasoning.
• Consider Pro tier for legal/data science.

Topics

• GPT-5.5
• Large Language Models
• AI Benchmarking
• Agentic AI
• API Pricing

Best for: CTO, VP of Engineering/Data, Machine Learning Engineer, AI Engineer, AI Scientist, Director of AI/ML

Related on AIssential

• GPT 5.5 — GPT-5.5 advances agentic AI, emphasizing practical, long-horizon task execution and token efficiency over raw benchmark gains.
• OpenAI just dropped GPT-5.5... (WOAH) — GPT 5.5 offers higher intelligence and token efficiency, especially for agentic coding and knowledge work, at a lower effective cost.
• GPT 5.5 LET'S GOOOOOOOO! — GPT-5.5 enhances agentic capabilities, coding performance, and multi-step task execution, signaling a shift towards more autonomous AI.
• What I Learned Testing GPT-5.5 — GPT 5.5 reclaims OpenAI's leadership in AI, excelling in "real work" tasks and agentic workflows.
• GPT-5.5 is HERE! — GPT 5.5 offers enhanced intelligence and token efficiency, particularly for coding and research, at a lower effective cost.
• I Tried The New GPT 5.5 And I’m Never Going Back — GPT 5.5 excels at complex task execution and agentic workflows, moving beyond simple query responses.

Open in AIssential →

Editorial summary, takeaway, and curation by AIssential. Original article published by VentureBeat.