GLM-5.3

Chinese large model developer Z.AI (formerly Zhipu AI) released GLM-5.3 on August 14, 2026, claiming it is the highest-ranked open-source model across multiple mainstream benchmarks, with coding and AI agent capabilities reportedly approaching those of Anthropic's Claude Fable 5. GLM-5.3 retains the same base model as GLM-5.3 scored 28.3% on Terminal-Bench 3.0 (measuring complex task completion in a real terminal environment), up from 4.6% for its predecessor GLM-5.2, compared with the 42.7% scored by Anthropic's closed-source Claude Opus 5, which ranks first on the benchmark. On DeepSWE v1.1 (focused on long-horizon software engine

Zhipu AI (智谱) released GLM-5.3 on August 14, 2026, describing it as the strongest open-weight model for coding and planning to publish weights two weeks after launch following additional security testing. The model retains the same base architecture as GLM-5.2, with all gains coming from post-training: Zhipu expanded Zhipu attributed the improvements to its IndexShare, SAO, and next-generation Slime reinforcement-learning frameworks rather than to a new model architecture, highlighting a broader shift where labs compete through post-training data, RL, and more demanding task environments. The company also reported an unexpected imp

GLM-5.3, announced on August 14, 2026, is a post-training-only release that uses the same base model as GLM-5.2, with every gain coming from post-training, according to Z.ai's GLM-5.3 blog and documentation. Z.ai frames it as "Frontier Coding with Emergent Cyber Capabilities," claiming a 50% coding gain over GLM-5.2 on Working with security teams in China, Z.ai reports GLM-5.3 surfaced 2,436 vulnerabilities across 269 projects, including 1,097 medium-to-high severity issues, with an average latent lifetime of 26.6 years and the oldest flaw introduced in 1981, describing unexpectedly fast growth in vulnerability discovery and exploita