Chrome DevTools for agents lets your coding agent analyze and fix client-side memory leaks (including JavaScript and WebAssembly) in your application. By automating the collection and analysis of heap snapshots, your agent can pinpoint objects that are not being properly garbage collected and suggest targeted code refactoring.
In an agentic workflow, your coding agent takes multiple snapshots across different application states and uses specialized analysis tools.
Common memory leak patterns
Memory analysis focuses on finding common leak patterns, including:
- Uncleared event listeners: Event listeners attached to global objects
(like
windowordocument) that prevent garbage collection. - Detached DOM nodes: Nodes removed from the document tree but still referenced by a JavaScript variable.
- Unintentional global variables: Variables declared without proper scoping that remain in memory forever.
- Closures: Closures that unintentionally keep references to large objects in their own scope.
- Unbounded data structures: Data structures used for caching that grow without limits.
Considerations for memory analysis
When using memory analysis, keep the following in mind:
Do not read raw snapshots directly: Do not let your agent read raw
.heapsnapshotfiles directly. They are too large and exceed context limits. The memory leak debugging skill explicitly instructs agents to avoid reading these files.The three-snapshot methodology: To find leaks reliably, your agent generally needs to capture three snapshots: a baseline before the action, a target after the action, and a final snapshot after reverting the action. Note that some actions, such as those triggered by timers (
setTimeout) or animations (requestAnimationFrame), occur without user interaction and might not require a reversal step.Note that some actions, such as those triggered by timers (
setTimeout) or animations (requestAnimationFrame), occur without user interaction and might still increase memory usage.Verify before fixing: Always review the agent's findings to ensure its proposed actions are applicable and correct for your application's logic. For example, confirm whether a detached node is part of an intentional cache before instructing the agent to nullify the references.
Use cases for memory leak analysis
Instruct your agent to profile memory during repetitive actions, including timers and user interactions, instead of manually taking snapshots and diffing them by hand. Integrate memory analysis into your debugging process with these workflows.
Note: Agent execution steps are examples of potential behavior. Your agent may act differently.
Detect uncleared event listeners during navigation
Single-page applications (SPAs) often leak memory when developers forget to remove global event listeners after a component unmounts. You can task your agent to verify that memory is correctly freed when navigating between views.
Example prompt:
Navigate from the home page to the dashboard and back to the home page. Use the take_heapsnapshot tool to check if we have any uncleared event listeners causing memory leaks.
Example agent execution: Your agent takes a baseline heap snapshot on the
home page, navigates to the dashboard, and navigates back to the home page to
take a final snapshot. It then uses internal analysis tools to evaluate
snapshots, detects that a scroll listener attached to the window object was
never cleared, and provides the specific code to call removeEventListener in
your component's cleanup function.
Identify detached DOM nodes in UI components
Modals, dropdowns, and complex UI components frequently leave behind detached DOM nodes if references to them are kept in JavaScript variables after they are removed from the DOM.
Example prompt:
Open the user settings modal and close it 5 times. Analyze the heap snapshots and tell me if there are any detached DOM nodes left behind. If there are, ask me if they are intentional before writing a fix.
Example agent execution: Your agent interacts with the settings modal while
collecting the required baseline, target, and final snapshots. The analysis
reveals several growing objects labeled as Detached HTMLDivElement. The agent
informs you of the finding and asks for your confirmation before changing the
code to set the variables holding the DOM references to null.
Find unbounded caches in continuous interactions
Features like infinite scrolling or continuous data fetching can leak memory if the underlying arrays or maps grow indefinitely without a cap.
Example prompt:
Scroll down the infinite feed list to load more items three times. Check if our LRU cache is unbounded and leaking memory, and suggest a fix.
Example agent execution: Your agent analyzes the memory state before and after scrolling. It identifies a closure that unintentionally captures a large array that grows without limits. The agent suggests implementing caching limits or using a WeakMap for data associated with the object life cycles to allow proper garbage collection.
Debug memory leaks in background processes
Animation and background timers can leak memory without explicit user interaction. You can instruct your agent to monitor memory growth over time to find memory leaks for these processes.
Example prompt:
Explore this canvas application and monitor memory usage. Help me determine areas of improvement around reusing objects and textures.
Example agent execution: Your agent explores the canvas application and automatically takes periodic snapshots to monitor memory usage over time. It analyzes the heap and identifies that the rendering loop pushes new WebGL meshes to an array on every frame without garbage collecting the previous ones, suggesting optimizations for object reuse.