OpenAI Adds Speed Control to GPT-5 Thinking, Launches GPT-5 Codex for Developers

OpenAI has rolled out a new update for ChatGPT users, introducing a feature that gives more control over how quickly GPT-5 with Thinking responds. Announced on September 18 via X, the feature is now available for Plus, Pro, and Business subscribers on the web.

GPT-5 Gets Speed Control

⏩ New Speed Control for GPT-5 Thinking

Previously, GPT-5 with Thinking responses were often slower, as the model was designed to reason deeply before generating answers. While powerful, many users wanted more flexibility to match different workflows.

With the update, subscribers can now choose pacing modes directly from the message composer:

• Standard: The new default, balancing speed and intelligence.

• Extended: Former Plus default, taking extra time for deeper responses.

• Quick: Pro-exclusive, delivering the fastest replies for short tasks.

• Heavy: Also Pro-exclusive, designed for the most comprehensive and careful reasoning.

OpenAI confirmed that the selected mode will remain active across chats until users manually change it.

“We’ve heard your feedback that GPT-5 Thinking can sometimes take longer than you’d like. Now Plus, Pro, and Business users can set the pace to match the moment,” OpenAI wrote on X.

💻 GPT-5 Codex for Developers

Alongside speed control, OpenAI has also introduced GPT-5 Codex, a new AI model tailored for software development. The tool is built to write, debug, and review code both interactively with humans and independently for long-running tasks.

OpenAI says GPT-5 Codex can:

• Create entire projects from scratch.

• Add new features to existing applications.

• Fix bugs and review code for errors.

• Work on projects independently for hours, testing and improving its own code.

For smaller tasks, it responds quickly without wasting resources, while for larger projects, it applies deep, methodical reasoning.

Tests on popular open-source projects showed that GPT-5 Codex provides more accurate and useful suggestions than earlier models, helping developers focus on critical issues instead of routine fixes.

🚀 Why This Matters

The update gives ChatGPT users greater flexibility in how they interact with AI, whether they need fast answers or deeper reasoning. At the same time, GPT-5 Codex could be a game-changer for developers by handling everything from simple bug fixes to long, autonomous coding sessions.