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
The open-weight model that dethroned GPT on SWE-bench Pro
50%
Panel ship
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Community
Paid
Entry
GLM-5.1 is Z.ai's (formerly Zhipu AI) latest open-weight model — a 744-billion-parameter Mixture-of-Experts architecture with 40B active parameters that claims the #1 spot on SWE-bench Pro with a score of 58.4, beating GPT-5.4 (57.7) and Claude Opus 4.6 (57.3). It ships under the MIT license with a 200K-token context window and maximum output of 131,072 tokens. What makes GLM-5.1 geopolitically notable is its training infrastructure: every GPU in the stack is a Huawei Ascend 910B — zero Nvidia hardware involved. This is one of the first frontier-competitive models to prove that non-Western AI compute can reach the top of benchmark leaderboards. It's a post-training upgrade to GLM-5, meaning architectural choices were locked in; the performance lift came from smarter RLHF and agentic training data. For developers, the value prop is straightforward: MIT license, frontier-level coding performance, and a 200K context window. The model is optimized for multi-step agentic tasks — it breaks down complex problems, runs experiments, reads results, and iterates. Real-world quality is still being validated beyond SWE-bench, but for teams that need a commercially-deployable open-weight coding model, this is the current benchmark king.
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
“MIT license plus 200K context plus #1 on SWE-bench Pro is a genuinely hard combination to ignore. If you're building coding pipelines and want frontier-level performance without API costs or licensing headaches, GLM-5.1 is currently the answer. Download weights, run inference, ship products.”
“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 Pro is one benchmark and we've watched leaderboards get gamed before. A 744B MoE model demands serious infrastructure — not something a solo dev or small team can spin up affordably. The Huawei-chip angle is interesting geopolitically but doesn't make deployment any easier for Western teams.”
“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.”
“A Chinese AI lab beats OpenAI and Anthropic on coding benchmarks, trained entirely on Huawei chips, released under MIT — that's three geopolitical norms shattered simultaneously. AI multipolarity isn't a future scenario anymore. GLM-5.1 is proof it's already here.”
“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.”
“Unless you're running serious coding infrastructure, a 744B model isn't your tool. You can't run this locally for UI copy or creative generation. Impressive benchmark news, but not something that moves the needle for design workflows.”
“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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