Web/API/StorageManager/estimate

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

The estimate() method of the StorageManager interface asks the Storage Manager for how much storage the current origin takes up (usage), and how much space is available (quota).

This method operates asynchronously, so it returns a Promise which resolves once the information is available. The promise's fulfillment handler is called with a StorageEstimate containing the usage and quota data.

Syntax

const estimatePromise = StorageManager.estimate();

Parameters

None.

Return value

A Promise that resolves to an object which conforms to the StorageEstimate dictionary. This dictionary contains estimates of how much space is available to the origin in StorageEstimate.quota, as well as how much is currently used in StorageEstimate.usage.

The returned values are not exact; between compression, deduplication, and obfuscation for security reasons, they will be imprecise.

You may find that the quota varies from origin to origin. This variance is based on factors such as:

How often the user visits
Public site popularity data
User engagement signals like bookmarking, adding to homescreen, or accepting push notifications

Example

In this example, we obtain the usage estimates and present the percentage of storage capacity currently used to the user.

HTML content

<label>
  You’re currently using about <output id="percent">
  </output>% of your available storage.
</label>

JavaScript content

navigator.storage.estimate().then(function(estimate) {
  document.getElementById("percent").value =
      (estimate.usage / estimate.quota * 100).toFixed(2);
});

Result

Specifications

Specification	Status	Comment
StorageThe definition of 'estimate()' in that specification.	Living Standard	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`estimate`	Chrome Full support 52	Edge Full support ≤79	Firefox Full support 51	IE No support No	Opera Full support Yes	Safari ?	WebView Android Full support 52	Chrome Android Full support 52	Firefox Android Full support 51	Opera Android Full support Yes	Safari iOS ?	Samsung Internet Android Full support 6.0

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown