Microsoft Edge Adds New Tools for Web Performance and AI Agents

Microsoft is adding new developer tools to Edge to help diagnose performance problems in modern single-page applications.

The company detailed the new Edge developer features, including new SPA performance metrics, JavaScript profiling improvements, network debugging tools, and WebMCP support for AI agents.

Edge can better track performance inside single-page apps

Single-page applications often update content without triggering a traditional browser navigation, making some performance problems harder to measure.

New soft-navigation and Interaction Contentful Paint performance entries can track these updates and help developers identify where slowdowns occur.

JavaScript profiling now provides more browser context

Microsoft is also adding JS Self-Profiling markers that show what Edge was doing when a performance sample was captured.

The markers can identify browser operations such as styling, layout, painting, and garbage collection, helping explain gaps in JavaScript profiling data.

The feature is currently available through an origin trial.

Edge 153 makes network requests easier to test

Microsoft Edge 153 adds new options for debugging network requests.

Developers can right-click a request to resend it or convert it into an editable Fetch request in the Console. They can then change headers, parameters, and other request details before sending it again.

Microsoft plans for these tools to eventually replace the experimental Network Console.

Microsoft has also acknowledged a separate issue where Edge 153 can completely freeze on web apps.

WebMCP could make websites easier for AI agents to use

Microsoft is testing WebMCP, a web API that lets websites expose existing functionality as structured tools for AI browsing agents.

Edge already includes a test implementation, sample projects, and a browser extension for debugging WebMCP tools.

Microsoft is also introducing the OpaqueRange API, which helps features such as spelling corrections and contextual pop-ups stay correctly positioned as users edit text.

Elsewhere, Microsoft plans to keep IE Mode available in Edge until at least 2029, while admins will receive seven days before Edge 154 removes WIP and MDAG.

Recent Canary testing also suggests Microsoft Edge Canary may disable Manifest V2 extensions.