Open weight

GLM-5.3 (Z.AI)

GLM-5.3 is Z.AI’s flagship coding and agent model. The lab describes it as the same base as GLM-5.2 with gains from post-training. Weights are public on Hugging Face as zai-org/GLM-5.3. Hosted access runs through Z.AI’s API and Coding Plan products.

Status: Current, open weights
AA score: 45 (max effort)Artificial Analysis Intelligence Index, one independent score across many tests, fetched 22 Sep 2026
Last checked: 22 Sep 2026newest source date on this page

On the Artificial Analysis Intelligence Index (fetched 22 Sep 2026 ET), GLM-5.3 (max) scores 45. The lighter sibling GLM-5.3-Flash scores 42. AA lists MiMo-V2.6-Pro ahead of GLM-5.3 among open weights on that fetch.

Training

Z.AI states that GLM-5.3 keeps the GLM-5.2 base and improves via post-training aimed at complex software engineering and long-horizon agent work. The research paper cited on the Hugging Face card is *GLM-5: from Vibe Coding to Agentic Engineering* (arXiv:2602.15763). Full dataset mix and FLOPs are not restated here beyond what the lab publishes.

Inference

Reasoning is always on. Effort levels are low, high, and max (default max). Text-only input on the docs page. Tool calling, streaming, structured output, and context caching are listed as supported. API protocols include OpenAI Chat Completions, OpenAI Responses, and Anthropic Messages via Z.AI endpoints.

Context

Documented context window: 1M tokens. Maximum output length on the docs page: 128K tokens.

Methods

Mixture-of-Experts architecture. Hugging Face and AA open-source materials list about 753B total parameters with about 40B active at inference. Serving recipes exist for SGLang, vLLM, TokenSpeed, Transformers, KTransformers, and Unsloth.

Benchmarking

Prefer Z.AI / Hugging Face tables for lab harness claims (coding, cyber, agent suites). Prefer AA for cross-lab Index comparison. Do not paste lab announce scores into AA Index cells. AA Index for GLM-5.3 (max): 45; GLM-5.3-Flash: 42 (leaderboard, 22 Sep 2026 ET).

Hardware and weights

Open weights: zai-org/GLM-5.3. License on Hugging Face is tagged other (custom glm-5.3 license on the model card). Read that license before redistribution or commercial packaging.

Access

Chat / product: z.ai
Docs: GLM-5.3 guide
API model id commonly documented as glm-5.3