Frequently Asked Questions

Table of contents:


Basic installation

To install Digital Carbon Online you need to insert two pieces of javascript code on every page that you want to measure.

The first piece of code loads the javascript library that will manage sending the data we need to the Digital Carbon Online server.

Library Load Snippet

<script type="text/javascript" src="">

The second piece records the page load in our database.

Record Page Snippet

<script type="text/javascript">

Once set up on the system you will receive an email with your unique authentication code.

The placement of these two pieces of script may be important in your web design. We generally recommend they are in the footer of your page, with Library Load Snippet before Record Page Snippet as shown below

<script type="text/javascript" src=""></script>
<script type="text/javascript">

You may decide to place the code in different locations in your page.

Verifying Correct Installation

Once installed, load your page and check the browser console for the message below.

Any other message such as the image below could indicate incorrect installation. In which case please check with your developer or read the Advanced Installation instructions below.

How to Find Your Browser Console

If you don’t know how to check your console, consult this article for guidance.

Advanced Installation

In certain situations you might want to delay the loading of the javascript. This might be to optimise page load speeds.

Delaying the loading of script files is typically done using the ‘defer‘ attribute. However this often leads to unpredictability when calling the Record Page Snippet.

We recommend an approach that executes the Record Page Snippet function only when the script is fully loaded. A combined example approach is below:

<script defer id="theScript" type="text/javascript" src=""></script>

<script defer type="text/javascript">
  theScript.addEventListener('load', function () {

In this example we’ve used the ‘defer‘ attribute in both script tags, but have also identified the library using an id ‘theScript‘.

We use this identifier to create a listener that executes the Record Page Snippet function once the library is fully loaded.

Other approaches might work better for your set up, so please ensure you check correct installation as mentioned above.


What data do we collect?

The only information sent to the Digital Carbon Online server are the URLs of visited web pages.

The server keeps a tally of how many times each unique URL is visited.

We keep data for unto 12 months, then it is deleted.

Data Security

Data security is paramount.

By default, any parameters that appear in the web page URL are discarded before the URL is sent to the server. This ensures no sensitive data is included in the process. 

Information is sent to the Digital Carbon Online server using industry standard secure HTTPS connections.

To ensure privacy and protection of private data, only publicly accessible pages are analysed. The carbon emissions of pages are determined using from our partner, Wholegrain Digital. Information is sent to the API using secure HTTPS connections.

Access to our databases is controlled by strong password encryption.

Clients have access to bespoke dashboards to explore and download their data. Access to these dashboards is via WordPress and protected by named accounts and industry standard strong password requirements.

WordPress is protected using industry leading firewall technologies. 

More details about our security practices are available on request.


When should I be able to see my data?

Assuming the code snippets have been correctly installed, data will be sent to our database every time a page is loaded/visited.

The data will not immediately appear in your private or public dashboards.

The data presented in your dashboards is summaries and aggregates data for monthly reporting, and is processed according to certain schedules and intervals.

It is not possible to determine the precise timing of the schedules since it is dependent on when the UK’s energy grid is at its lowest carbon intensity. More information can be found about this in our blog article here.

As described in that article, if the energy network has not achieved a low carbon intensity for a few weeks, we will process the data anyway to ensure you have access to the reports and data on a monthly basis.

Your first month

When you first register and install the code in your website, we are happy to provide confirmation that data is being received. Simply email support [at] with your domain name and unique authorisation code.

Since the reporting is monthly, your first reports will be available after one full month of operation.


“Weighing” pages

Digital Carbon Online leverages the nascent webpage carbon calculation standard as being defined by the Green Web Foundation.

The process of determining the carbon dioxide emissions of a web page is a complex affair that is based on the energy required to transfer data, and involves assumptions about where energy is used during the transmission of data required to deliver a web page. The methodology defined by the Green Web Foundation, splits these assumptions across energy used by the end user device, the networks and the server.

Fundamental the Green Web Foundation’s methodology relies on understanding the size (in bytes) of a web page.

Digital Carbon Online takes two approaches to determining the page size; one approach gives a ‘best case’ (or ‘lighter’) estimation of the page size, the other gives a ‘worst case’ (or ‘heavier’) estimation.

Both data points are captured, used and presented within Digital Carbon Online to help users understand that the true CO2 weight of a page isn’t a single number, but a range.

These two approaches are designated in the Digital Carbon Online dashboards as the “Standard Model” (representing the best case) and the “Alt Model” (representing the worst case).

digital carbon online dual model reporting example-min-2