GLM-5.3 Flash is live on Novita AI as zai-org/glm-5.3-flash. Z.ai describes it as a native multimodal model for coding and long-horizon agent tasks, and Novita exposes it through a serverless, pay-per-token API.
Quick Take: GLM-5.3 Flash Specs
- Model ID:
zai-org/glm-5.3-flash - Context window: 1M tokens
- Max output: 128K tokens
- Input: text, image, video
- Output: text
- Price on Novita: $0.075 / 1M input tokens, $0.25 / 1M output tokens
What GLM-5.3 Flash Is for Coding Agents
Z.ai says GLM-5.3 Flash is the first native multimodal model in the GLM-5 family. The launch notes also describe a hybrid architecture that combines sparse and linear attention, which is meant to keep long-context behavior accurate while reducing compute overhead.
That makes the model a fit for workflows that do not stay in one modality. A coding agent might need a screenshot, a rendered UI state, a bug report, and a patch plan in the same loop. For a text-only baseline, compare it with GLM 5.2 on Novita AI and GLM-5.1 API on Novita AI. GLM-5.3 Flash is built for that kind of task mix.
Novita AI Specs and Pricing
| Field | Value |
|---|---|
| Model | zai-org/glm-5.3-flash |
| Provider | Z.ai |
| Access | Serverless API |
| Base URL | https://api.novita.ai/openai |
| Context length | 1M |
| Max output | 128K |
| Input capabilities | Text, image, video |
| Output capabilities | Text |
| Input price | $0.075 / 1M tokens |
| Output price | $0.25 / 1M tokens |
Why GLM-5.3 Flash Matters for Multimodal Workflows
The main appeal is not just the multimodal input. It is the combination of multimodal input, long context, and low hosted pricing. That is useful for:
- coding agents that inspect screenshots and code together
- browser or UI workflows that need visual feedback
- long-running tasks that keep state across many turns
- internal tools that need both retrieval and visual context
If your workload is text-only and short, a smaller model may still be the simpler choice. For a multimodal reference point, see GLM-4.6V on Novita AI.
Start a GLM-5.3 Flash Request
from openai import OpenAI
client = OpenAI(
api_key="<Your API Key>",
base_url="https://api.novita.ai/openai",
)
response = client.chat.completions.create(
model="zai-org/glm-5.3-flash",
messages=[
{"role": "system", "content": "You are a concise coding assistant."},
{"role": "user", "content": "Summarize the tradeoffs in this bug report."},
],
max_tokens=4096,
)
print(response.choices[0].message.content)For image or video prompts, follow the Novita API docs for multimodal message formatting.
Conclusion
GLM-5.3 Flash gives developers a hosted multimodal model for coding agents and long-running workflows, with text, image, and video input, a 1M-token context window, and 128K-token maximum output. On Novita AI, the serverless API and pay-per-token pricing make it practical to evaluate alongside GLM 5.2 and GLM-5.1 before choosing a model for production.
FAQ
Is GLM-5.3 Flash multimodal?
Yes. Novita lists text, image, and video input support.
What is the model ID?
zai-org/glm-5.3-flash
Is it free?
No. Novita lists pay-per-token pricing.
What is the context window?
1M tokens.
