Secure context

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

The StorageEstimate dictionary's usage property is a conservative approximation of how much storage is allotted to the origin or Web app that called StorageManager.estimate(); there may be more space available, but there will not be less. The value is an estimate because the user agent may use compression, duplication prevention techniques, and other methods to improve storage efficiency.


usage = StorageEstimate.usage;


A numeric value specifying an approximation of the total amount of storage space available for use by the application.


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

HTML content

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

JavaScript content {
  document.getElementById("percent").value =
      (estimate.usage / estimate.quota * 100).toFixed(2);



Storage Standard (Storage)
# dom-storageestimate-usage

Browser compatibility

BCD tables only load in the browser

See also