GLM-5.3-Flash - Zhipu's open-source native multimodal model, namely Ox Alpha.

Technical Principles of GLM-5.3-Flash

• Hybrid attention architectureGLM-5.3-Flash adopts a hybrid architecture of linear attention and sparse attention. Linear attention captures local dependencies through a recursive mechanism, while sparse attention recalls the global context with the help of a lightweight indexer. At the same time, the introduction of IndexPool compresses the indexer cache vector from 4 to 1, which reduces the attention computation and KV cache by 3.01 times and 4.44 times respectively compared to GLM-5.3, significantly reducing service costs while maintaining accurate long context capabilities.
• Manifold-constrained hyperconnections (mHC)The model employs mHC technology to enhance scaling capabilities, reducing the number of activation parameters from 32B to 18B and the number of layers from 92 to 45, while maintaining a total parameter count of 320B, comparable to GLM-4.5. Combined with a 30T token multimodal pre-training corpus, it achieves performance exceeding that of GLM-5.2 with fewer computational resources.
• Domestic chip inference engineTo address the memory capacity and bandwidth bottlenecks of domestically produced chips, the team built a dedicated inference engine on top of SGLang. They adopted an EPD (Encode-Prefill-Decode) split architecture to separate multimodal encoding, prefilling, and decoding into independent working pools. Combined with tensor parallelism, ReplaySSM, W8A8 quantization, and hybrid cache quantization, the end-to-end performance was improved by 3 times compared to the baseline, achieving efficiency comparable to mainstream NVIDIA GPUs.

Follow us on WeChat and reply with "open source",join inAI open source project discussion group

How to use GLM-5.3-Flash

• BigModel APIVisit the BigModel Open Platform (https://docs.bigmodel.cn/cn/guide/models/vlm/glm-5.3-flash) to register an account, obtain the API Key, and then use it according to the documentation. glm-5.3-flash interface.
• Z.ai APIVisit the Z.ai API official website https://docs.z.ai/guides/vlm/glm-5.3-flash documentation center, register and obtain an API Key to access the model.
• Z.ai online chatVisit the Z.ai website, log in, and start a multimodal conversation directly.
• Zhipu Qingyan AppDownload the Zhipu Qingyan App and log in. Then select GLM-5.3-Flash from the model list to use it.
• ZCodeEnter ZCode, enable the model, and let the Agent collaborate in the code editor to complete the development task.
• AutoClawVisit the AutoClaw website, upload your documents, and let the model automatically handle office and professional document tasks.
• Open source local deploymentDownload the model weights from HuggingFace and load and run them on your local server as instructed.
• GLM Coding PlanVisit https://bigmodel.cn/glm-coding to apply for a limited trial card and try out the model capabilities for free.

The core advantages of GLM-5.3-Flash

• Ultimate cost-effectivenessIt's a smart phone in the same class as the Claude Opus 4.8, but priced at only 1/40th of it, and during a limited-time discount, it's 1/20th of the price of the GLM-5.3.
• Native MultimodalThe first native multimodal model in the GLM-5 series, with natively integrated visual capabilities, capable of autonomously judging and invoking visual feedback.
• High-efficiency architectureThe architecture employs a hybrid approach of sparse attention and linear attention, which reduces attention computation and key-value caching by 3.01 times and 4.44 times respectively compared to GLM-5.3.
• Deployment of domestically produced chipsThis marks the first large-scale use of domestically produced chip clusters, resulting in a 3x improvement in end-to-end performance compared to the baseline, with efficiency comparable to mainstream NVIDIA GPUs.
• Completely surpassing its predecessorWith 320B total parameters / 18B activation parameters, it outperforms GLM-5.2, which has twice the number of parameters, in multiple benchmark tests.
• Professional work optimizationIt is deeply optimized for professional scenarios such as finance, law, and Office documents, and the output format can be delivered directly.

Comparison of GLM-5.3-Flash with similar competing products