GLM-5.3 Flash
Z.ai · #4 in our ranking · Best value
GLM-5.3 Flash is an open-weight mixture-of-experts model from Z.ai, released Aug 2026, with 320B parameters (18B active per token), a 1M-token context window, and the MIT.
GLM-5.3 Flash starts from a new base model with hybrid sparse and linear attention, which cuts long-context serving costs. With 18B active parameters it is cheap to run, and Z.ai reports it approaching Claude Opus 4.8 on coding and agentic benchmarks.
GLM-5.3 Flash specs
- Provider
- Z.ai
- Architecture
- Mixture-of-experts
- Parameters
- 320B total · 18B active
- Context
- 1M tokens | 786K words
- License
- MIT Commercial use
- Input
- Text, Image
- Released
- Aug 2026
- Weights
- Hugging Face
Sourced from the model card on Hugging Face. Last checked 2026-10-01.
Highlights
- 18B active parameters
- MIT license
- Image input and 1M context
Where it fits for payment teams
- Partner-bank RFIs
#2 pick. Image input at 18B active parameters and an MIT license, a cost-effective default for high RFI volume.
- Transaction monitoring
#2 pick. 18B active parameters with strong agentic skills for the enrichment queries behind each alert.
- KYC and KYB checks
#2 pick. Image input, MIT license, and low cost for high onboarding volume.
- Payments customer support
#1 pick. Low cost at 18B active parameters with strong tool use for account lookups.
Harnesses in Runtime
Run GLM-5.3 Flash through any of these harnesses on Runtime.
How to run GLM-5.3 Flash
Download the weights
Pull zai-org/GLM-5.3-Flash from Hugging Face. Check the MIT before you deploy.
Serve it in your cloud
Run it with vLLM or SGLang on your own GPUs, or use a managed provider that hosts the model.
Put it to work in Runtime
Point an agent or a single skill at the model through OpenCode, then compare it to your current model with evals.
GLM-5.3 Flash FAQ
What is the context window of GLM-5.3 Flash?
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GLM-5.3 Flash supports a 1M-token context window (1,048,576 tokens), roughly 786K words of English text.
How many parameters does GLM-5.3 Flash have?
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GLM-5.3 Flash is a mixture-of-experts model with 320B total parameters, of which 18B are active per token.
Is GLM-5.3 Flash free for commercial use?
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Yes. GLM-5.3 Flash is released under the MIT license, which is permissive and allows commercial use and fine-tuning.
What can GLM-5.3 Flash take as input?
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GLM-5.3 Flash accepts text, image input and generates text.
Is GLM-5.3 Flash good for partner-bank RFIs?
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Yes. GLM-5.3 Flash is our #2 pick for partner-bank RFIs. Image input at 18B active parameters and an MIT license, a cost-effective default for high RFI volume.
Is GLM-5.3 Flash good for transaction monitoring?
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Yes. GLM-5.3 Flash is our #2 pick for transaction monitoring. 18B active parameters with strong agentic skills for the enrichment queries behind each alert.
Is GLM-5.3 Flash good for KYC and KYB checks?
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Yes. GLM-5.3 Flash is our #2 pick for KYC and KYB checks. Image input, MIT license, and low cost for high onboarding volume.
Is GLM-5.3 Flash good for payments customer support?
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Yes. GLM-5.3 Flash is our #1 pick for payments customer support. Low cost at 18B active parameters with strong tool use for account lookups.
Can I run GLM-5.3 Flash in my own cloud with Runtime?
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Yes. Download the weights from Hugging Face (zai-org/GLM-5.3-Flash) and serve them with vLLM or SGLang in your cloud, or use a managed provider that hosts the model. Runtime agents can then use GLM-5.3 Flash through a harness like OpenCode, with your data staying in your environment.