# GPT-5.3-Codex-Spark

> OpenAI's ultra-fast, real-time coding model on Cerebras silicon

- Maker: OpenAI
- Line: Codex
- Canonical page: https://ai-tldr.dev/models/gpt-5-3-codex-spark/
- Updated: 2026-06-18

## In short

GPT-5.3-Codex-Spark is OpenAI's ultra-fast, text-only coding model, released on February 12, 2026 as a research preview for ChatGPT Pro subscribers inside the Codex app, the Codex CLI, and the IDE/VS Code extension. It has a 128K-token context window. You can use it through OpenAI.

## Facts

| Fact | Value | Source |
| --- | --- | --- |
| Context window | 128K tokens (max output Not disclosed by OpenAI) | [1] |
| Licence | Proprietary (OpenAI). Closed model, no public weights; access via ChatGPT Pro and limited design-partner API. · API only | [1] |
| Released | 12 February 2026 | [2] |
| Parameters | Not disclosed (OpenAI describes it only as "a smaller version of GPT-5.3-Codex") | [1] |
| Knowledge cutoff | Not officially published for the Spark variant | [1] |

## Sources

1. [OpenAI Developers — Codex models (model list)](https://developers.openai.com/codex/models)
2. [OpenAI — Introducing GPT-5.3-Codex-Spark (official announcement)](https://openai.com/index/introducing-gpt-5-3-codex-spark/)

## Overview

GPT-5.3-Codex-Spark is OpenAI's ultra-fast, text-only coding model, released on February 12, 2026 as a research preview for ChatGPT Pro subscribers inside the Codex app, the Codex CLI, and the IDE/VS Code extension. OpenAI positions it as a smaller, speed-optimized version of GPT-5.3-Codex built for real-time, in-the-moment coding — making targeted edits, reshaping logic, and refining interfaces with results that feel near-instant rather than for long, multi-step autonomous runs.

The defining feature of Codex-Spark is throughput: it streams more than 1,000 tokens per second when served on ultra-low-latency hardware. That hardware is the Cerebras Wafer-Scale Engine 3 (WSE-3), making Codex-Spark OpenAI's first model deployed on production silicon outside its long-standing Nvidia stack. OpenAI calls this the first milestone in its multi-billion-dollar partnership with Cerebras, with the research preview kept narrow while the two companies ramp datacenter capacity. At launch the model is text-only with a 128k-token context window.

OpenAI frames Codex-Spark as the complement to the full GPT-5.3-Codex rather than a replacement: Spark for rapid iteration and immediate feedback, the larger Codex for deeper reasoning and long-running tasks. OpenAI says Spark produces more capable responses than GPT-5.1-Codex-mini while finishing agentic-engineering tasks (evaluated on SWE-Bench Pro and Terminal-Bench 2.0) in a fraction of the time of the full Codex, but did not publish absolute benchmark percentages for the Spark variant, and noted that for heavy multi-step reasoning the larger Codex models still win on absolute quality.

## Strengths

- Extreme generation speed — over 1,000 tokens per second, roughly an order of magnitude faster than the full GPT-5.3-Codex
- Near-instant feedback loop ideal for iterative, interactive coding (targeted edits, refactors, UI tweaks)
- First OpenAI model on Cerebras WSE-3, sidestepping GPU memory-wall and interconnect latency
- 128k context window, enough for active files and immediate project dependencies
- More capable than GPT-5.1-Codex-mini per OpenAI, while being far faster than full Codex
- Integrated directly into the Codex app, CLI, and IDE extension for ChatGPT Pro users

## Best for

- Rapid prototyping and quick iteration on code where latency matters
- Targeted, in-the-moment edits — reshaping logic or refining a function and seeing results immediately
- Interactive frontend/UI loops where you tweak and re-run constantly
- Pair-programming-style real-time collaboration inside the Codex CLI or IDE
- Fast subtasks where you'd otherwise wait on a slower frontier model
- Demos and live coding where near-instant output keeps the flow going

## How to access

- [OpenAI](https://developers.openai.com/codex/models) — model id `gpt-5.3-codex-spark`

## Codex versions

- [GPT-5.3-Codex](https://ai-tldr.dev/models/gpt-5-3-codex/) (5 February 2026)
- GPT-5.3-Codex-Spark (12 February 2026) — this page
- [GPT-5.2-Codex](https://ai-tldr.dev/models/gpt-5-2-codex/) (11 December 2025)
- [GPT-5.1-Codex](https://ai-tldr.dev/models/gpt-5-1-codex/) (19 November 2025)
- [GPT-5-Codex](https://ai-tldr.dev/models/gpt-5-codex/) (September 2025)

## FAQ

### What is GPT-5.3-Codex-Spark?

It is OpenAI's ultra-fast, text-only coding model, released February 12, 2026 as a research preview for ChatGPT Pro users. It is a smaller, speed-optimized version of GPT-5.3-Codex, built for real-time coding — quick edits and iteration with near-instant output rather than long autonomous runs.

### How fast is GPT-5.3-Codex-Spark?

OpenAI says it streams more than 1,000 tokens per second when served on ultra-low-latency hardware, roughly an order of magnitude faster than the full GPT-5.3-Codex. That speed comes from running on the Cerebras Wafer-Scale Engine 3 (WSE-3).

### Why does it run on Cerebras instead of Nvidia?

Codex-Spark is OpenAI's first model deployed on production silicon outside its long-standing Nvidia stack, marking the first milestone in OpenAI's partnership with Cerebras. The WSE-3's single-wafer design with on-chip memory enables the very low latency and high throughput Spark needs for real-time coding.

### Can I use GPT-5.3-Codex-Spark in the API, and is it still available?

At launch it was a research preview for ChatGPT Pro users in the Codex app, CLI, and IDE extension, with only limited API access for design partners — OpenAI did not publish a per-token API price. Unlike the full GPT-5.3-Codex, which OpenAI began retiring in mid-2026, Codex-Spark was exempted from those deprecations and remained available.

## Links

- [OpenAI — Introducing GPT-5.3-Codex-Spark (official announcement)](https://openai.com/index/introducing-gpt-5-3-codex-spark/)
- [OpenAI Developers — Codex models (model list)](https://developers.openai.com/codex/models)
- [OpenAI Developers — Codex pricing](https://developers.openai.com/codex/pricing)
- [Cerebras — Introducing OpenAI GPT-5.3-Codex-Spark, powered by Cerebras](https://www.cerebras.ai/blog/openai-codexspark)
- [TechCrunch — A new version of OpenAI's Codex is powered by a new dedicated chip](https://techcrunch.com/2026/02/12/a-new-version-of-openais-codex-is-powered-by-a-new-dedicated-chip/)
- [Help Net Security — OpenAI released GPT-5.3-Codex-Spark, a real-time coding model](https://www.helpnetsecurity.com/2026/02/13/openai-gpt-5-3-codex-spark/)
- [Tom's Hardware — OpenAI launches GPT-5.3-Codex-Spark on Cerebras chips](https://www.tomshardware.com/tech-industry/artificial-intelligence/openai-lauches-gpt-53-codes-spark-on-cerebras-chips)
- [Wikipedia — GPT-5.3-Codex](https://en.wikipedia.org/wiki/GPT-5.3-Codex)

Source: AI/TLDR LLM registry, https://ai-tldr.dev/models/gpt-5-3-codex-spark/