LockManager: query() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2022.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is available in Web Workers.

The query() method of the LockManager interface returns a Promise that resolves with an object containing information about held and pending locks.

Syntax

js
query()

Parameters

None.

Return value

A Promise that resolves with an object containing a snapshot of the LockManager state. The object has the following properties:

held

An array of LockInfo objects for held locks.

pending

An array of LockInfo objects for pending lock requests.

The LockInfo object can have the following properties:

name

The name passed to LockManager.request() when the lock was requested.

mode

The access mode passed to LockManager.request() when the lock was requested. The mode is either "exclusive" or "shared".

clientId

The unique identity of the context where LockManager.request() is called. This is the same value as Client.id.

Exceptions

This method may return a promise rejected with a DOMException of one of the following types:

InvalidStateError DOMException

Thrown if the environments document is not fully active.

SecurityError DOMException

Thrown if a lock manager cannot be obtained for the current environment.

Examples

js
const state = await navigator.locks.query();
for (const lock of state.held) {
  console.log(`held lock: name ${lock.name}, mode ${lock.mode}`);
}
for (const request of state.pending) {
  console.log(`requested lock: name ${request.name}, mode ${request.mode}`);
}

Specifications

Specification
Web Locks API
# api-lock-manager-query

Browser compatibility

desktop mobile server
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Node.js
query
Chrome – Full support
Chrome 69 (Release date: 2018-09-04)
footnote Full support
Edge – Full support
Edge 79 (Release date: 2020-01-15)
footnote Full support
Firefox – Full support
Firefox 96 (Release date: 2022-01-11)
footnote Full support
Opera – Full support
Opera 56 (Release date: 2018-09-25)
footnote Full support
Safari – Full support
Safari 15.4 (Release date: 2022-03-14)
footnote Full support
Chrome Android – Full support
Chrome Android 69 (Release date: 2018-09-04)
footnote Full support
Firefox for Android – Full support
Firefox for Android 96 (Release date: 2022-01-11)
footnote Full support
Opera Android – Full support
Opera Android 48 (Release date: 2018-11-08)
footnote Full support
Safari on iOS – Full support
Safari on iOS 15.4 (Release date: 2022-03-14)
footnote Full support
Samsung Internet – Full support
Samsung Internet 10 (Release date: 2019-08-22)
footnote Full support
WebView Android – Full support
WebView Android 69 (Release date: 2018-09-04)
footnote Full support
WebView on iOS – Full support
WebView on iOS 15.4 (Release date: 2022-03-14)
footnote Full support
Node.js – Full support
Node.js 24.5 (Release date: 2025-07-31)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support