The Save-Data is a HTTP request-type header. It is used to indicate whether the client wants to turn on data saving mode or not. Here, data usage is measured in terms of cost and performance. The role of any browser is to provide optimized user experience by providing the highest possible level of performance in a minimal amount of cost.
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Save-Data: On
It indicates that the user wants to enable data-saving mode.
-
Save-Data: Off
It indicates that the user wants to disable data-saving mode.
Browsers supporting this, give the option of switching to and from the data-saving mode. If the data-saving mode is active then the browser is in a position to perform optimization techniques such as text or image compression, which in turn will reduce the amount of data that is to be utilized by the page.
Syntax:
Save-Data: <sd-token>
Directives: This header accept a single directive as mentioned above and described below.
- <sd-token>: It indicates whether data saving mode is turned on or off.
Example 1:
With Save-Data: With save data we will check both the header type Request and Response.
- Request header:
GET /googlelogo.png HTTP/1.0 Host: www.google.com Save-Data: on
- Response header:
HTTP/1.0 200 OK accept-ranges: bytes cache-control: private, max-age=31536000 content-length: 5969 content-type: image/png date: Thu, 14 May 2020 04:18:11 GMT expires: Thu, 14 May 2020 04:18:11 GMT last-modified: Tue, 22 Oct 2019 18:30:00 GMT server: sffe status: 200 x-content-type-options: nosniff x-xss-protection: 0
Example 2:
Without Save-data: Without save data we will check both the header type Request and Response.
- Request header:
GET /googlelogo.png HTTP/1.0 Host: www.google.com
- Response header:
HTTP/1.0 200 OK accept-ranges: bytes cache-control: private, max-age=31536000 content-length: 1018 content-type: image/png date: Thu, 14 May 2020 04:18:11 GMT expires: Thu, 14 May 2020 04:18:11 GMT last-modified: Tue, 22 Oct 2019 18:30:00 GMT server: sffe status: 200 x-content-type-options: nosniff x-xss-protection: 0
Note: The only difference in the output is that when save-data mode is enabled then the content-length is much lower than when the save-data mode is disabled.
Supported Browsers: The browsers are supported by HTTP Save-Data header are listed below:
- Google Chrome
- Microsoft Edge
- Opera
- Firefox