OpenAI Launches GPT-5.3-Codex-Spark

OpenAI has introduced a new AI coding model called GPT-5.3-Codex-Spark. The company describes it as its first real-time code writing AI model capable of writing and refining code instantly with ultra-low latency. The model runs on low-latency hardware and is specifically designed for developers. Currently, it is available in limited research preview access.

OpenAI Launches GPT-5.3-Codex-Spark

OpenAI has taken a major step in the coding domain by launching GPT-5.3-Codex-Spark, a real-time AI model built to accelerate software development workflows. The new model focuses on instant code generation and editing, signaling OpenAI’s growing emphasis on AI-powered development tools in 2026.

Increased Focus on Codex

In 2026, OpenAI elevated the Codex model lineup to a higher strategic priority. Recently, the company released GPT-5.3-Codex, which launched ahead of the general-purpose model. OpenAI CEO Sam Altman described Codex’s growth as extremely rapid, mentioning a 50 percent increase within just one week.

With the introduction of Codex-Spark, OpenAI has now taken a direct step toward real-time coding capabilities. This move reflects the company’s stronger commitment to AI-driven software development tools.

What Makes GPT-5.3-Codex-Spark Special?

Real-Time Code Generation

The biggest strength of GPT-5.3-Codex-Spark is its ability to generate and edit code in real time. According to the company, the model can almost instantly write code, make edits, and reshape logic structures.

• Processes approximately 1,000 tokens per second

• Designed as a text-only model

• Focused on code-level improvements, interface refinement, and targeted editing

• Offers a 128,000-token context window

This context window enables it to handle standard and moderately complex development tasks efficiently. For more complex tasks, OpenAI recommends using the GPT-5.3-Codex model.

Specialized Hardware Partnership

The high speed of Codex-Spark is powered by low-latency hardware. OpenAI recently partnered with Cerebras Systems, and Codex-Spark runs on the company’s Wafer Scale Engine 3 AI accelerator.

Internal benchmark tests suggest:

• Better performance than GPT-5.1-Codex-mini

• Slightly lower performance than GPT-5.3-Codex

• Significant speed advantage due to hardware optimization

Availability and Access

GPT-5.3-Codex-Spark is currently available to ChatGPT Pro subscribers via:

• Codex app

• CLI

• IDE extension

It is being offered as a research preview to limited users. Access through API is also available to select design partners. OpenAI plans to expand access in the coming weeks.

Key Highlights at a Glance

• First real-time AI coding model from OpenAI

• Processes up to 1,000 tokens per second

• 128,000-token context window

• Powered by Cerebras Wafer Scale Engine 3

• Optimized for developers and software engineering workflows

• Limited research preview access