Z AI released GLM-5.3-Flash on August 26, 2026, an open-weight reasoning model with 320 billion total parameters and 18 billion active parameters per inference token. The Mixture-of-Experts model accepts text and image inputs, produces text outputs, and supports a 1 million-token context window. Its weights are available on Hugging Face under the MIT license, which permits commercial use. Artificial Analysis gave GLM-5.3-Flash a score of 57 on its Intelligence Index, compared with a median score of 27 for open-weight models of a similar size. The composite benchmark covers reasoning, knowledge, mathematics and coding. The evaluation generated 150 million output tokens, above the comparable-model median of 110 million, indicating relatively verbose outputs. Z AI's API charges $0.15 per million input tokens and $0.50 per million output tokens; Artificial Analysis lists a blended cache-hit/input/output rate of $0.10 per million tokens using a 7:2:1 ratio. The Intelligence Index evaluation cost $138.02. The model produces about 50.2 tokens per second, below the comparable median of 65.8, while its 1.56-second time to first token is faster than the 2.13-second median.