What is this?

This knowledgebase contains questions and answers about PRTG Network Monitor and network monitoring in general.

Learn more

PRTG Network Monitor

Intuitive to Use. Easy to manage.
More than 500,000 users rely on Paessler PRTG every day. Find out how you can reduce cost, increase QoS and ease planning, as well.

Free Download

Top Tags

View all Tags

What does the Cloud HTTP sensor measure as Response Time



The Cloud HTTP Sensor, (currently in Beta: https://www.paessler.com/manuals/prtg/cloud_http_sensor), is returning a "Response Time" channel.

What is the measure behind this metric: "time to first byte", "document load", or something else?

Thanks Thomas

cloud-http cloud-sensor http https prtg-cloud

Created on May 6, 2015 4:52:05 PM

5 Replies



Document load is the time it took to load the entire page without it's linked assets (i.e. css files). Wikipedia defines the Time-To-First-Byte like this:

Time To First Byte

...is a measurement that is often used as an indication of the responsiveness of a webserver or other network resources.

It is the duration from the virtual user making an HTTP request to the first byte of the page being received by the browser. This time is made up of the socket connection time, the time taken to send the HTTP request, and the time taken to get the first byte of the page.

Link to full article

What other metrics were you talking about? :)

Created on May 12, 2015 1:14:30 PM by  Stephan Linke [Paessler Support]



Hi Stephan,

Thanks but I know what TTFB and Document Load mean, the question is:

The Cloud HTTP Sensor [...] is returning a "Response Time" channel. What is the measure behind this ["Response Time"] metric?

Thanks Thomas

Created on May 12, 2015 2:42:31 PM



Well you asked for it :)

The response time represents the time the server took to fully process the requested page (i.e. deliver it to the client) until a response code is sent to the client. More on that can be found here.

Created on May 13, 2015 10:53:17 AM by  Stephan Linke [Paessler Support]



Thanks Stefan, that's what I was looking for: the time between the request sent and the document is fully downloaded. Can you confirm that the test doesn't load extra elements, just the main page? (e.g. CSS, JS, etc.)

I'm looking for equivalence between the Catchpoint metrics and the PRTG cloud HTTP sensor.

I realise that my question was confusing, sorry about that.

Created on May 13, 2015 1:26:56 PM



As far as I know, assets are not loaded - I'll ask the developer just to make sure :)

Just asked the developer - all assets are loaded, just like when you load the file in a browser. The only exception are javascripts, they're not executed. Additionally, the request has to be completed within 5,000ms :)

Created on May 14, 2015 7:58:20 AM by  Stephan Linke [Paessler Support]

Last change on May 14, 2015 8:21:41 AM by  Stephan Linke [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.