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 first open-source model to beat GPT-5.4 and Claude Opus on real-world coding
50%
Panel ship
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Community
Paid
Entry
GLM-5.1 is a 754-billion parameter open-weights language model released by Z.ai (formerly Zhipu AI) under the MIT license on April 7, 2026. It topped the global SWE-Bench Pro leaderboard with a score of 58.4 — surpassing GPT-5.4 (57.7), Claude Opus 4.6 (57.3), and Gemini 3.1 Pro (54.2) — marking the first time an open-source model has outperformed all leading closed-source models on a widely-cited real-world code repair benchmark. Built on a Mixture-of-Experts architecture and trained entirely on Huawei Ascend 910B chips with zero Nvidia involvement, GLM-5.1 was designed for long-horizon agentic coding. Internal demos showed the model sustaining autonomous task execution for over 8 hours across complex multi-file codebases. The full weights weigh in at 1.51TB on Hugging Face, making self-hosting a serious infrastructure undertaking — but the Z.ai API provides accessible access for teams that can't run the model locally. The significance here is hard to overstate: open-source has spent two years chasing the frontier on coding benchmarks, and GLM-5.1 just crossed it. MIT licensing means commercial use without royalties, and training on non-Nvidia hardware is a notable signal that the hardware moat around frontier AI is cracking. Expect rapid community fine-tunes and distillations in the weeks ahead.
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
“A 754B MIT-licensed model that actually beats GPT-5.4 on SWE-Bench Pro is the kind of release you stop what you're doing for. The API is live today and the weights are on Hugging Face. If you're building coding tools, agentic pipelines, or anything touching code generation, this is a must-benchmark 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.”
“1.51TB to self-host is not practical for 99% of teams, and SWE-Bench Pro captures one narrow slice of what makes a model useful in production. The 8-hour autonomous demo sounds impressive until you realize that's a cherry-picked task — real enterprise coding pipelines are messier. The API pricing will matter more than the benchmark.”
“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 first open-source model to beat all closed frontier models on a meaningful coding benchmark is an inflection point. The story of sovereign AI, non-Nvidia training stacks, and MIT-licensed weights converging in one model release is the geopolitical tech story of 2026. Distillations will bring this capability to consumer hardware within months.”
“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.”
“This is a tools-for-engineers release with zero direct value for creators right now. The downstream effect — better open-source coding agents that help build creative tools — will matter eventually. Wait for the apps built on top of it.”
“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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