AI tool comparison
GLM-5.1 vs GPT-5.5
Which one should you ship with? Here is the side-by-side panel verdict, pricing read, reviewer split, and community vote comparison.
AI Models
GLM-5.1
#1 on SWE-Bench Pro — 744B MoE model that runs autonomously for 8 hours
50%
Panel ship
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Community
Paid
Entry
GLM-5.1 is Z.AI's post-training upgrade of the 744B Mixture-of-Experts GLM-5 model, and it has just claimed the top spot on SWE-Bench Pro with a score of 58.4 — beating GPT-5.4 (57.7), Claude Opus 4.6 (57.3), and Gemini 3.1 Pro (54.2). The model is designed for long-horizon agentic tasks and can run autonomously for up to 8 hours across thousands of iterations on a single problem. The agentic capabilities include extended context retention, tool-calling with recovery loops, and a reinforcement-trained "persistence" mode that keeps the model on-task through failures and dead ends rather than surfacing errors to the user. The model was trained entirely on Huawei Ascend 910B chips using the MindSpore framework — no US silicon, no CUDA. The geopolitical dimension is as significant as the technical one: GLM-5.1 is direct evidence that US export controls on Nvidia hardware have not meaningfully slowed China's frontier model development. The 8-hour autonomous execution window is also a step-change from current agentic systems that struggle past 20-30 minutes of coherent work — if this benchmark holds up in real-world testing, it's a genuine advancement in the class of problems AI agents can independently solve.
AI Models
GPT-5.5
OpenAI's new flagship unifies chat, code, and browser into one agent
75%
Panel ship
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Community
Free
Entry
OpenAI shipped GPT-5.5 on April 23, 2026, positioning it as "a major step toward a unified AI super-app" that combines chat, coding, and browser use in a single model. It is accessible via a new Agent Mode dropdown inside ChatGPT for Pro, Plus, and Team subscribers, and through the API for developers. The model delivers stronger tool use and reliability than its predecessors, with particular improvements in multi-step agentic task completion. New workspace agents for ChatGPT Business and Enterprise can autonomously handle tasks across Slack, Gmail, and other connected platforms — the same territory OpenAI has been building toward since the Agents SDK launch earlier this year. GPT-5.5 is OpenAI's answer to growing pressure from Anthropic's Claude Opus 4.7, Google's Gemini Enterprise platform, and open-source contenders like Kimi K2.6 and Arcee Trinity. Whether it actually leapfrogs the competition or merely matches it is still shaking out in independent benchmarks, but for the millions of existing ChatGPT users, it's the biggest capability jump they'll feel in day-to-day use this year.
Reviewer scorecard
“If the 8-hour autonomous execution claim is real and not cherry-picked, this changes the calculus for using AI on genuinely hard engineering problems. SWE-Bench Pro #1 is also a credible metric — I want to test this on my own repos immediately.”
“The API reliability improvements alone make this worth upgrading. Multi-step tool use has been the weak link in production OpenAI deployments — if GPT-5.5 actually fixes flakiness in function calling chains, that's worth the token cost increase.”
“SWE-Bench benchmarks have historically shown poor correlation with real-world coding productivity, and the '8-hour autonomous' claim needs independent validation. Z.AI is also a relatively unknown quantity compared to Anthropic or Google — API reliability and pricing are completely unproven.”
“OpenAI's release cadence has become so fast that GPT-5.5 may already feel dated by the time you integrate it. Independent benchmark results are inconsistent — some put it behind Kimi K2.6 on coding. And the 'unified super-app' framing is marketing; you're still paying separately for every capability.”
“The strategic significance of a Chinese lab hitting #1 on the coding benchmark using zero US hardware cannot be overstated. The export control strategy is officially not working as intended, and GLM-5.1 will accelerate the geopolitical AI arms race in ways that reshape the entire industry.”
“The Slack and Gmail workspace agents are the real story — they bring agentic AI to the office worker who will never touch an API. OpenAI's distribution advantage means GPT-5.5 will be the most-used AI model on the planet within weeks of launch, regardless of benchmark rankings.”
“For creative work, I need a model with strong multimodal capabilities and reliable API access — both unproven for GLM-5.1. The coding benchmark lead is impressive but not directly relevant to my workflows. I'll wait for independent reviews before switching.”
“Agent Mode in ChatGPT is finally making AI feel less like a chatbot and more like a collaborator. For creators who live in a browser, having a model that can autonomously browse, research, and draft without constant hand-holding is a genuine time multiplier.”
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