devtools_memory

Memory panel. snapshot captures a .heapsnapshot artifact (opens in DevTools Memory) and summarizes objects by class with sizes and detached DOM node count. compare diffs two snapshots by class (growth). retainers lists what holds instances of a class. sampling start/stop records an allocation sampling profile (.heapprofile) with top allocating functions. usage returns current heap size; growth samples heap usage over time to spot leaks.

The tool names stay the same across browsers. See browser selection and Firefox and Zen exceptions before choosing an operation.

Heap snapshots, class diffs, retainers and allocation sampling need Chromium developer mode because extensions cannot use HeapProfiler. usage and growth also work in Chromium extension mode. Firefox and Zen do not support this tool.

Parameters

integer

Target tab id from browser_tabs, which lists tabs across all windows. Defaults to the agent’s most recently opened usable tab, or the only usable tab. Otherwise select a listed tabId.

enum

required

One of: snapshot, compare, retainers, sampling, usage, growth, list.

string

integer

enum

For sampling One of: start, stop.

integer

number

growth: duration, default 10

boolean

Collect garbage first (default true for snapshot)

Example

{
  "tabId": 5001,
  "action": "snapshot"
}

Growth between two snapshots

{
  "tabId": 5001,
  "action": "compare",
  "snapshotId": "snap-2",
  "other": "snap-1"
}

Sample heap usage for 20 seconds

{
  "tabId": 1234,
  "action": "growth",
  "seconds": 20,
  "gc": true
}

Browser automation

Developer tools

Parameters

Example

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Parameters

Example