A small badge in your website footer can do a useful job: it tells visitors you have looked at your site's footprint and lets them see the evidence for themselves. GreenTracer offers two, a carbon badge and a green hosting badge. They look alike, but they answer different questions, and neither is a certificate. This article explains what each one shows, where it leads, how it dates, and how to talk about it without overclaiming.
The carbon badge: one page, one date
The carbon badge reads “Carbon grade” followed by the grade from your report, from A+ to F, with the date of the check in the corner. The grade comes from one check of one page: GreenTracer loads the page once with Google PageSpeed Insights on mobile and desktop, estimates emissions per page view from the heavier of the two runs using the Sustainable Web Design Model v4, and places that estimate in a band. Our rating page lists the bands.
That makes the badge a statement about a page on a date. It isn't a measurement of your whole website, and it certainly isn't a figure for your organisation. If you check your home page and put the badge on every page of the site, the badge is still describing the home page. Clicking it opens your public GreenTracer report, where anyone can see which page was checked, the estimate, and how it was worked out.
The hosting badge: your host's listing
The hosting badge has only two possible messages. It reads “Hosting: Listed as green” only when your host appears in The Green Web Foundation's dataset. In every other case, including when we couldn't complete the check, it reads “Hosting not confirmed”. Like the carbon badge, it shows the date of the check and links to your report, opening at the section that explains the hosting result.
It helps to know what that listing is. The Green Web Foundation describes its directory as “a searchable list of verified green hosting providers”. The listing is about the hosting provider, based on evidence the provider submitted, and the Foundation notes that its data may contain errors. So a hosting listing is useful information about who serves your site, but it isn't proof about your particular site, and it doesn't say anything about how heavy your pages are. For more on what to ask a host, see green hosting proof without greenwashing.
Dates, and when a badge goes out of date
Websites change. A new hero photo or an extra script can move a page from one band to another, and hosting arrangements change too. That's why both badges carry the date of the check, and why they don't stay “current” for ever:
- Carbon badge: a carbon result is treated as out of date 180 days after the check. From then on the badge no longer shows the old grade; it shows “Last checked” with the date and “Recheck pending”.
- Hosting badge: the hosting check goes out of date sooner, after 90 days, and the badge then reads “Hosting not confirmed” until the hosting is checked again.
- Refreshing: the badge updates when you check your website again. Nothing rechecks it automatically, so make a habit of checking again after you change the page or move host, and before the dates above come round.
An out-of-date badge isn't a disaster, but it does tell visitors that the evidence is old. A recent date is more convincing than any wording you could add.
Which one to show, or both
- Show the carbon badge if you want to point people to a result for a page you've worked on. A grade you can explain is more useful than a perfect one.
- Show the hosting badge if your host is listed as green and you want visitors to be able to see that listing, with its date.
- Show both if both are true and current. They sit well side by side because they say different things.
- Skip the hosting badge if it would say “Hosting not confirmed”. The badges page suggests showing only the carbon grade badge in that case.
You can choose a badge, pick a light or dark style and copy the code on the badges page. Please don't edit or recreate the badge image; the point of it is that the badge and the report agree.
Words to put next to a badge
If you mention your badge on an “About” or sustainability page, the UK's Green Claims Code is a good test. Among its principles: claims must be truthful and accurate, clear and unambiguous, must not omit or hide important relevant information, and must be substantiated. It also warns that a claim can mislead by giving an inaccurate impression even when it is factually correct. In practice:
- Say what was checked. “Our home page was rated B by GreenTracer in October 2026” is clear. “Our website is certified green” is not true, because a badge is not a certification.
- Call the estimate an estimate. The figure comes from a model, not a meter, and the model's authors describe it as imprecise by nature.
- Name the source of the hosting claim. “Our host is listed as green by The Green Web Foundation” is accurate. “Our website runs on 100% renewable energy” is a different claim that the listing alone doesn't prove.
- Avoid absolute words. Neither badge makes a site “green”, “carbon neutral” or “zero emission”.
- Let the link do the work. Each badge leads to the public report, so visitors can see the date, the page and the method rather than taking your word for it.
Haven't got a report yet? Check your page, then read how to read a website carbon report before you decide which badge says what you want to say.