Codex adds Chrome DevTools Protocol support for web app debugging
Codex now supports the Chrome DevTools Protocol (CDP) within its Browser Use functionality, enabling it to inspect console logs, runtime errors, network traffic, local storage, applied styling, and performance profiles while debugging web applications.
Score breakdown
CDP support lets Codex move from static code review to live runtime analysis, enabling it to identify and validate real performance bottlenecks in a running web application rather than relying on code inspection alone.
- 01Codex now supports the Chrome DevTools Protocol (CDP) within its Browser Use functionality.
- 02CDP access enables performance profiling, network traffic inspection, console log review, runtime error inspection, local storage access, and applied styling examination.
- 03A demo shows Codex debugging a slow chat app by profiling interactions and inspecting network requests, then fixing issues and supporting fixes with clear measurements.
Codex's Browser Use functionality has been extended with support for the Chrome DevTools Protocol (CDP), allowing the agent to go beyond surface-level code inspection and directly interact with a running web application's internals. The new capabilities include performance profiling, network traffic inspection, console log and runtime error review, local storage access, and applied styling examination — tools that mirror what a developer would use manually in a browser's DevTools panel.
Codex then fixed the issues and presented clear measurements to support the improvements, demonstrating that the agent can both diagnose and validate fixes rather than simply suggesting code changes.
The demo illustrates the practical impact: a chat app that had slowed down noticeably as its conversation list grew was handed to Codex, which profiled specific interactions and examined network requests to identify the true bottlenecks. Codex then fixed the issues and presented clear measurements to support the improvements, demonstrating that the agent can both diagnose and validate fixes rather than simply suggesting code changes.
Because CDP gives Codex deeper insight into the application it controls, a two-step opt-in is required: users must first enable Developer Mode in the Codex app's browser settings, then explicitly approve when Codex starts using CDP to inspect a website. Further documentation is available at the OpenAI Codex developer reference under the browser developer-mode section.
Key facts
- 01Codex now supports the Chrome DevTools Protocol (CDP) within its Browser Use functionality.
- 02CDP access enables performance profiling, network traffic inspection, console log review, runtime error inspection, local storage access, and applied styling examination.
- 03A demo shows Codex debugging a slow chat app by profiling interactions and inspecting network requests, then fixing issues and supporting fixes with clear measurements.
- 04Codex uses CDP to identify true bottlenecks rather than performing a code-only pass.
- 05To use the feature, Developer Mode must be enabled in Codex's browser settings.
- 06Users must explicitly approve when Codex starts using CDP to inspect a website.
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