Question 1

What is the cost of GPT-5.3 Chat by ZenMux?

Accepted Answer

GPT-5.3 Chat by ZenMux costs $1.75 per 1M input tokens and $14.00 per 1M output tokens.

Question 2

What is the context window of GPT-5.3 Chat by ZenMux?

Accepted Answer

GPT-5.3 Chat by ZenMux has a context window of 128K tokens. It supports up to 128K input tokens and can generate up to 16K output tokens.

Question 3

What are the capabilities of GPT-5.3 Chat by ZenMux?

Accepted Answer

GPT-5.3 Chat by ZenMux supports tool calling/function calling, adjustable temperature, file attachments. It has closed weights.

Question 4

What input and output types does GPT-5.3 Chat support?

Accepted Answer

GPT-5.3 Chat by ZenMux accepts text as input and can generate text as output.

Question 5

Is GPT-5.3 Chat by ZenMux open source?

Accepted Answer

No, GPT-5.3 Chat by ZenMux has closed weights. The model is only available through the ZenMux API.

Question 6

Does GPT-5.3 Chat support function calling?

Accepted Answer

Yes, GPT-5.3 Chat by ZenMux supports tool calling (also known as function calling), allowing it to interact with external tools and APIs during conversations.

Question 7

What is the knowledge cutoff date for GPT-5.3 Chat?

Accepted Answer

GPT-5.3 Chat by ZenMux has a knowledge cutoff date of 2025-08-31. This means the model was trained on data available up until that date.

GPT-5.3 Chat API

Input Modalities

Output Modalities

Standard (per 1M tokens)