What is an ETag in HTML header?

The ETag (or entity tag) HTTP response header is an identifier for a specific version of a resource. It lets caches be more efficient and save bandwidth, as a web server does not need to resend a full response if the content was not changed.

How do I check ETag headers?


  1. Load the web page that you want to test.
  2. Hit F12 to open the Developer Tools.
  3. Switch to the Network Tab.
  4. Reload the page.
  5. Check the main page element first, usually at the top.
  6. ETag should be listed under Response Headers on the right side.

What is ETag header vulnerability?

Description. The remote web server is affected by an information disclosure vulnerability due to the ETag header providing sensitive information that could aid an attacker, such as the inode number of requested files.

What is ETag in REST API?

REST and ETags An ETag (entity tag) is an HTTP response header returned by an HTTP/1.1 compliant web server used to determine change in content at a given URL. We can use ETags for two things – caching and conditional requests. The ETag value can be thought of as a hash computed out of the bytes of the Response body.

What does ETag stand for?

An entity tag (ETag) is an HTTP header used for Web cache validation and conditional requests from browsers for resources. Etags use persistent identification elements (PIE) that have been tagged to the user’s browser.

How do I get an ETag?

What you need

  1. your personal or business details.
  2. the vehicle’s details, including the state the vehicle is registered in (it doesn’t have to be NSW)
  3. your Australian Business Number (ABN) or Australian Company Number (ACN) (if applicable)
  4. the registration fee (for an E-Toll Tagless Account)

How do I find my ETag number?

Your tag number is the unique 10 to 12-digit serial number printed on your tag device. To find a list of all your tag numbers, log in to your account and select Tags from the menu. If you want to transfer a toll invoice or notice to your account, you’ll need your tag number.

How do ETag headers work?

The ETag (or Entity Tag) works in a similar way to the Last-Modified header except its value is a digest of the resources contents (for instance, an MD5 hash). This allows the server to identify if the cached contents of the resource are different to the most recent version.

How is an ETag made?

ETag generation The method by which ETags are generated has never been specified in the HTTP specification. Common methods of ETag generation include using a collision-resistant hash function of the resource’s content, a hash of the last modification timestamp, or even just a revision number.

How do I register for ETag?

Where do I register an e-toll account?

  1. Visiting SANRAL e toll customer service centres, located at a mall or along the Gauteng e-road.
  2. Registering online at sanral.co.za etoll.
  3. Printing the registration form available from the e-toll website and faxing it to 0800 726 725 or emailing it to [email protected].