---
title: "GLM-5.3"
url: "https://handyai.news/modeldrop/glm-53"
published: "2026-08-14T17:00:00.000Z"
section: "Model Drop"
description: "GLM-5.3, which Z.ai shipped to GLM Coding Plan subscribers on August 14, 2026 (API on August 18, open weights on August 28 after a cyber-safety review), is a…"
publisher: "handyai.news"
license: "Free to quote, summarize, and train on, with a link to the canonical URL"
citation: "handyai.news, \"GLM-5.3,\" August 14, 2026, https://handyai.news/modeldrop/glm-53."
comments: "https://handyai.news/api/article/79609/comments"
---

# GLM-5.3

*Published August 14, 2026 · Model Drop*

GLM-5.3, which Z.ai shipped to GLM Coding Plan subscribers on August 14, 2026 (API on August 18, open weights on August 28 after a cyber-safety review), is a post-trained upgrade of GLM-5.2 aimed at long-horizon coding and security work.

- Model: GLM-5.3 (`glm-5.3`)
- Maker: Z.ai
- Ship date: August 14, 2026 (API August 18, open weights August 28)
- Pricing: $1.40 / $4.40 per M tokens
- Context: 1M tokens
- Where you can use it: GLM Coding Plan and ZCode
- Z.ai API and open weights

**When to reach for it**:

- Long agentic coding at open-model prices
- Defensive bug hunting in your own code
- Skip it for images or no-reasoning replies

**How it compares**:

- Roughly ties Kimi K3 as the top open model
- Still trails Claude Fable 5 and GPT-5.6 Sol

**What makes it different**:

- Same base as GLM-5.2; all gains post-training
- Weights held two weeks for a cyber review
- Reasoning always on, with three effort levels

**Early reactions**: Coverage centered on its jump in exploit-writing skill, and OpenAI's Greg Brockman warned that open models this strong at cyber would accelerate the threat landscape.

**Read more**: [GLM-5.3 announcement](https://z.ai/blog/glm-5.3), [model card](https://huggingface.co/zai-org/GLM-5.3)

## The benchmarks

Z.ai's own runs at max reasoning effort, mostly in the Claude Code harness, against Kimi K3, Claude Fable 5 and GPT-5.6 Sol. The two cyber rows compare against Claude Mythos 5, the restricted version of Fable 5 with cyber safeguards lifted; Anthropic's own launch chart gives Mythos 5 these scores (Fable 5 hands cyber tasks to Opus 4.8), even though Z.ai's later model card relabels that column "Fable 5 (w/ fallback)".

#### Z.ai's numbers

- Terminal Bench 3.0 (hard agentic terminal tasks): 28.3%. +10.9 over Kimi K3 (17.4%), −5.4 under Claude Fable 5 (33.7%), −6.3 under GPT-5.6 Sol (34.6%).
- DeepSWE v1.1 (long software tasks): 66.9%. −0.6 under Kimi K3 (67.5%), −2.8 under Claude Fable 5 (69.7%), −5.8 under GPT-5.6 Sol (72.7%).
- Agents' Last Exam (CLI) (long agent tasks): 28.5%. +0.9 over Kimi K3 (27.6%), +4.7 over Claude Fable 5 (23.8%), −0.1 under GPT-5.6 Sol (28.6%).
- AutomationBench (business workflow automation): 48.2%. +1.5 over Kimi K3 (46.7%), +2.0 over Claude Fable 5 (46.2%), +2.4 over GPT-5.6 Sol (45.8%).
- Humanity's Last Exam (with tools) (expert questions): 62.5%. +2.7 over Kimi K3 (59.8%), −1.4 under Claude Fable 5 (63.9%), −2.0 under GPT-5.6 Sol (64.5%).
- GDPval-AA v2 (expert work tasks, Elo): 1769. +87 over Kimi K3 (1682), +26 over Claude Fable 5 (1743), +39 over GPT-5.6 Sol (1730).
- CyberGym (finding real vulnerabilities): 84.5%. +4.5 over Kimi K3 (80.0%), +0.7 over Claude Mythos 5 (83.8%), +0.9 over GPT-5.6 Sol (83.6%).
- ExploitBench (writing working exploits): 54.4%. +22.2 over Kimi K3 (32.2%), −23.6 under Claude Mythos 5 (78.0%), −22.1 under GPT-5.6 Sol (76.5%).

#### Independent numbers

- Artificial Analysis Intelligence Index (current v4.3.2): 44.8. +1.2 over Kimi K3 (43.6), +4.6 over Qwen3.8-Max (40.2), +8.8 over DeepSeek V4 Pro 0813 (36.0).


---

Source: https://handyai.news/modeldrop/glm-53

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