GLM-5.3 scores 84.5pc on CyberGym, ahead of Anthropic’s Mythos 5 and OpenAI’s GPT-5.6 Sol.

Chinese AI company Z.ai has unveiled its latest open-weights model – GLM-5.3 – whose performance, it said, rivals that of the newest OpenAI and Anthropic frontier launches, marking the latest in the ever-escalating battle between US and Chinese companies for AI dominance.

The new model makes a significant leap in capability compared to its predecessor GLM-5.2, which launched in June.

GLM-5.3 is “much better” at complex coding and long-horizon tasks, Z.ai said, boasting a 50pc improvement from the older version in its in-house code benchmarks.

The company plans to release GLM-5.3’s weights in two weeks’ time, after wrapping up safety evaluation and hardening.

“[GLM-5.3] delivers markedly stronger agentic coding results than GLM-5.2 at every effort level while consuming fewer output tokens,” Z.ai said.

GLM-5.3 also proves significantly capable at exploiting vulnerabilities, scoring 84.5pc on CyberGym, above Anthropic’s Mythos 5 and OpenAI’s GPT-5.6 Sol.

“We expected this to make the model better at finding and reasoning about vulnerabilities. What surprised us was how quickly the capability continued to develop as training scaled,” Z.ai said.

Despite its lofty claims about the new model, the Hong Kong-listed company’s shares slid nearly 4pc by market close today (14 August).

“This firm remains on a completely unsustainable commercial footing,” intelligence analyst Robert Lea told Bloomberg. “Rising agentic AI will drive Z.ai’s inference costs and losses higher.”

Chinese-made models are increasingly offering performances on par with American counterparts at cheaper prices, in spite of the heavy constraints around chip exports into the country. Last month, Z.ai completed the construction of a data centre where it has installed at least 10,000 Chinese-made chips to help develop its GLM line of models.

Other frontier offerings from China, including Moonshot’s latest Kimi model, DeepSeek’s V4 models and Alibaba’s Qwen series, have all ranked highly in benchmarks and testing.

Beijing-based start-up Z.ai went public in January this year, raising funds at a market capitalisation of nearly $7bn.

Shares at the company surged 2,000pc in June following the launch of GLM-5.2, taking Z.ai’s valuation to $128bn, though that has since fallen to around $75bn.

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