carbon.txt - What is it and Why is it Important

Yearly, ImageEngine is preventing thousands of tonnes CO2 from being emitted into the atmosphere. Thanks to our customers.

On top of that, ImageEngine is carbon neutral. ImageEngine compensate for 100% of the unavoidable carbon footprint originating from running our infrastructure.

This is an easy claim for anyone to make. How can this be verified?

Enter carbon.txt

Like the heading suggests, the core of the concept is a text file named carbon.txt. This text file is available for anyone to view or crawl. Similar to the better known cousin robots.txt.

carbon.txt is an initiative from The Green Web Foundation (TGWF), and ImageEngine is happy to be the first CDN to natively support this initiative!

How does carbon.txt work?

The basic idea is that carbon.txt should be available on the root of your website: https://mywebsite.com/carbon.txt. Just like what we're used to with robots.txt.

The contents of the text file documents upstream providers of resources used by the website, such as hosting, analytics, media etc. Moreover, references to sustainability policies, offset schemes etc. belonging to the organization owning the website. The last part is optional, but of course, we highly recommend to establish a sustainability policy as a competitive advantage.

This information is represented using TOML syntax.

The basic idea is to make the entire "graph" of emissions visible and crawlable.

ImageEngine's implementation

Because ImageEngine is a CDN, ImageEngine will by default serve any content which is available at the origin. For example, if your origin mapped to an engine has a carbon.txt file at its root, the engine will serve the same file from the engine root. This file is yours, and does not represent ImageEngine's sustainability policy.

Instead, you may notice a specific HTTP header returned on all responses from ImageEngine:

Via: 1.1 https://imgeng.in/carbon.txt <signature>

This is how ImageEngine refers to the canonical location of its carbon.txt file: https://imgeng.in/carbon.txt

Because of this reference, TGWF, and other entities maintaining a database of green providers, will be able to see that images on your website are carbon neutral, served from green infrastructure and/or emissions being offset properly.

With ImageEngine, this comes out of the box. We also recommend to create a carbon.txt for your website which is using ImageEngine

Example of carbon.txt for ImageEngine customers

Here's an example of how a carbon.txt file might look for an ImageEngine customer.

[upstream]
providers = [
    { domain = "netlify.com", service = "shared-hosting" },
    { domain = "imageengine.io", service = "cdn" }
]

[org]
credentials = [
     # Optional, but if you have a sustainability policy, you can reference it here.
    { domain = "yoursite.com", doctype = "webpage", url = "https://yoursite.com/sustainability/"}
]

• The upstream providers are Netlify for hosting and ImageEngine for media optimization.
• If you have proprietary resources relevant for sustainability, you can list those as credentials
• If adding a new file at the document root is not an option, you can also refer to it in a TXT record in your DNS: TXT "carbon-txt=https://my-org.com/otherlocation/carbon.txt <signature>"

Conclusion

ImageEngine is listed and verified as a "green provider" in their fast growing Green Hosting Directory.

ImageEngine's built in support for carbon.txt ensures transparency and evidence of our commitment to our sustainability policy for our customers and anyone else looking to reduce the digital footprint.

More information about the initiative can be found here.