GLM-5.3-Flash is a native multimodal model from Z.ai. It is suited for efficient coding and long-horizon agent tasks. Its hybrid sparse and linear attention architecture maintains accurate long-context behavior while sharply reducing serving cost. 320B total / 18B active parameters, 1M-token context, text + image + video in, text out.
OpenAI-compatible — keep the SDK you already use
https://api.orcarouter.ai/v1https://api.orcarouter.aiimport os
from openai import OpenAI
client = OpenAI(
base_url="https://api.orcarouter.ai/v1",
api_key=os.environ["ORCAROUTER_API_KEY"],
)
response = client.chat.completions.create(
model="z-ai/glm-5.3-flash-free",
messages=[{"role": "user", "content": "Hello"}],
)
print(response.choices[0].message.content)include_reasoningmax_tokensreasoningreasoning_effortresponse_formatstopstreamtemperaturetool_choicetoolstop_p| Per request | $0 |
|---|---|
| Billing | Model usage is never charged to your balance |
| Over the limit | HTTP 429 when a limit is hit |
Need it without the limits? z-ai/glm-5.3-flash·How free-tier limits work →
What developers are saying this week
GET /api/public/models/z-ai/glm-5.3-flash-freeOpen @misc{orcarouter_glm_5_3_flash_free,
title = {GLM 5.3 Flash (Free) API},
author = {Z.ai},
year = {n.d.},
howpublished = {OrcaRouter},
url = {https://www.orcarouter.ai/models/z-ai/glm-5.3-flash-free}
}Z.ai. (n.d.). GLM 5.3 Flash (Free) API. OrcaRouter. https://www.orcarouter.ai/models/z-ai/glm-5.3-flash-free