Z.ai · Model release
GLM 5.3 Flash: Z.ai's lower-cost multimodal model
Z.ai's August 2026 model page describes GLM 5.3 Flash and its hosted API. Treat the earlier 'Ox Alpha' identity attribution as community reporting, not an independently established release fact.
What changed
- Z.ai describes the architecture and efficiency claims in its release; those are vendor-reported design claims.
- Z.ai claims roughly 3× lower attention compute and a 4× smaller KV cache versus base GLM-5.3 at long context, from the hybrid sparse/linear-attention design.
- Use the current Z.ai rate table for this exact API model and cache class; third-party host rates and aliases can differ.
Best fit
- Cost-efficient long-context work
- Multimodal input pipelines
- Coding agents on a budget
What to be careful about
- Hardware requirements depend on exact weights, quantization, runtime and context; use an inference-provider's supported recipe or benchmark your intended setup.
- Any benchmark comparison needs the same board version, model variant, effort and test harness; no universal rank is claimed here.
- Text, image and video input only — no audio input and no built-in web search.
Dataset snapshot: GLM 5.3 Flash is also represented in the checked comparison dataset. Prices and benchmark figures carry their own field dates.