GLM-5.3 (Reasoning)
by Zhipu AI
GLM-5.3 (Reasoning) is a reasoning model from Zhipu AI, released on August 14, 2026. It has a 1M-token context window and can generate up to 1M output tokens. API pricing is $1.2 per 1M input tokens and $4 per 1M output tokens. It ranks #10 of 220 models by Intelligence Score with a score of 51.5.
GLM-5.3 is Z.AI's open-weight flagship for complex coding, long-horizon agentic work, and cybersecurity tasks. It uses the same base model as GLM-5.2, with its capability gains coming from post-training. The Hugging Face checkpoint is a text-only 753B-parameter MoE (about 40B active) with 78 layers, 256 routed experts plus one shared expert, eight routed experts selected per token, DeepSeek Sparse Attention with IndexShare, and a 1,048,576-token context window. It supports up to 128K output tokens, function calling, structured output, context caching, and always-on thinking with low, high, and max reasoning-effort levels. The downloadable FP8 and BF16 weights are available under the custom GLM-5.3 License, which permits use, modification, redistribution, sale, deployment, and fine-tuning but requires Model-as-a-Service businesses above US$10B in annual revenue to pass a Z.AI security review before commercial use.
Key specs
| Provider | Zhipu AI |
|---|---|
| Release date | 2026-08-14 |
| License | open weights |
| Context window | 1M tokens |
| Max output | 1M tokens |
| Input price | $1.2 / 1M tokens |
| Output price | $4 / 1M tokens |
| Intelligence Score | 51.5 |
| Coding index | 40.5 |
Quick answers
What is the context window of GLM-5.3 (Reasoning)?
GLM-5.3 (Reasoning) has a context window of 1M tokens, with a maximum output of 1M tokens per response.
How much does GLM-5.3 (Reasoning) cost?
GLM-5.3 (Reasoning) costs $1.2 per 1M input tokens and $4 per 1M output tokens through the API.
Is GLM-5.3 (Reasoning) open source?
Yes. GLM-5.3 (Reasoning) is an open model released under the open weights license.
When was GLM-5.3 (Reasoning) released?
Zhipu AI released GLM-5.3 (Reasoning) on August 14, 2026.
How does GLM-5.3 (Reasoning) compare to Claude Opus 5.5 (Reasoning)?
GLM-5.3 (Reasoning) scores 51.5 on the Intelligence Score versus 60.5 for Claude Opus 5.5 (Reasoning), the current #1. Input pricing is $1.2 vs $4 per 1M tokens.
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