GLM 5.3 is available now on Fireworks

Model Library
/Z.ai/GLM 5.3 Flash
model path:accounts/fireworks/models/glm-5p3-flash

GLM-5.3-Flash is the first natively multimodal model in the GLM-5 series with 320B total parameters and 18B active parameters. It incorporates several architectural improvements over GLM-5.2 including a hybrid architecture, sharply reducing long-context serving costs while preserving precise long-context and Manifold-Constrained Hyper-Connections (mHC) to further improve scaling efficiency.

GLM 5.3 Flash API Features

Serverless

Docs

GLM 5.3 Flash is available via Fireworks' serverless API, where you pay per token. There are several ways to call the Fireworks API, including Fireworks' Python client, the REST API, or OpenAI's Python client.

On-demand Deployment

Docs

On-demand deployments allow you to use GLM 5.3 Flash on dedicated GPUs with Fireworks' high-performance serving stack with high reliability and no rate limits.

Available Serverless

Run queries immediately, pay only for usage

$0.15 / $0.029 / $0.50
Per 1M Tokens (input/cached input/output)

Metadata

State
Ready
Created on
8/26/2026
Kind
Base model
Provider
Z.ai

Specification

Calibrated
No
Mixture-of-Experts
No
Parameters
320B

Supported Functionality

Fine-tuning
Not supported
Serverless
Supported
Context Length
1040k tokens
Function Calling
Supported
Embeddings
Not supported
Rerankers
Not supported
Support image input
Supported