Privacy and cookies
How we handle your data
This page is our privacy policy and our cookie policy in one place. It explains what GreenTracer collects when you check a website, what becomes public, and the choices you have.
Last updated: 11 October 2026
Who we are
GreenTracer is a free website carbon checker, currently in beta. It is operated by BuzzBoost Digital Ltd, a company registered in England and Wales (company number 15960977), registered office 26 Northview Drive, Westcliff-on-Sea, Essex, SS0 9NG (“we”, “us”). We decide how the personal data described here is used, which makes us the controller of that data under UK data protection law.
For anything about your data, email support@buzzboost.co.uk.
In short
- When you check a website, the address you enter and the result are saved and published as a public report.
- Giving your email is optional. We use it to send your report, and for updates only if you tick the separate opt-in.
- Our badges tell us which web page they are shown on, so we can show the right result and see where badges are installed.
- Analytics only run if you accept them. Rejecting is as easy as accepting, and you can change your mind at any time.
- We do not sell personal data.
What we collect and why
When you check a website
We take the web address (URL) you enter and use it to measure the page. To do that, we send the URL to Google PageSpeed Insights, which loads the public page and reports how much data it transfers. We send the website’s hostname (for example, example.com) to The Green Web Foundation to ask whether the host is listed as green.
We then save the result: the URL, the measured page weight, the hosting status, the carbon estimate, the grade and the date of the check. If the page cannot be measured, nothing is saved.
A website address is not usually personal data. It can be, though, if it contains a name or other details about a person. Please do not check addresses that include private information.
If you give us your email address
Adding your email when you check a website is optional. If you do, we store:
- your email address;
- the website you checked and a link to its report;
- which form you used;
- whether you ticked the box to receive occasional updates.
We use your email to send you the report. When email sending is switched on, this goes through our email provider, SendGrid. We only send you updates if you ticked the opt-in, and you can ask us to stop at any time.
If you tick the opt-in, we also keep a record of your consent: your email address, the exact wording you agreed to, when you agreed and where. Every email sent to you because of that opt-in includes an unsubscribe link, and unsubscribing is recorded with its date. Asking for a report or contacting us never adds you to updates on its own.
Contact messages
Messages sent through the contact form go by email to BuzzBoost Digital Ltd, which runs GreenTracer, so we can reply. They are not stored in GreenTracer's database. If you choose the topic about help improving your website, BuzzBoost may reply about its web services; this is optional and never changes a report, grade or badge.
Member accounts
A small number of existing members have accounts. For them we store their sign-in details (handled by our database provider’s login service), the domains linked to their account, their membership status and the badge information needed to run their dashboard.
Paid features are not currently on sale. If we introduce them, we will update this policy and our terms of use first.
When you visit the site
Like most websites, the companies that host our site and server receive your IP address and basic technical details (such as your browser type) when you load a page or run a check. We use this to deliver the site, to limit how many checks can be run in a short time, and to keep the service secure.
Our pages also load fonts from Google Fonts, which means your browser connects to Google to fetch them.
Public reports
Every result is published as a public report page at an address like greentracer.org/result/example-com. Anyone with the link can view it, and report addresses may be listed so that search engines can find them. The report shows the page that was checked, its estimated emissions, its grade, its hosting status and the date of the check.
When the same page is checked again, the earlier results are kept and shown as history on the report.
Your email address is never shown on a report, and a report does not say who ran the check.
If a report concerns your website and you would like us to review or remove it, email support@buzzboost.co.uk with the report link.
Badges on other websites
Website owners can add a GreenTracer badge to their site. The badge is loaded by a small script from our server. When the badge appears on a page, the script sends us:
- the full address of the page the badge is on;
- the website’s hostname, and the domain the badge is set up for;
- the type of badge and, where there is one, the report it links to.
We record when a badge was first and last seen, and how often it loads. We use this to show the correct result, to spot badges shown on the wrong website, and to show members where their badge is installed. Like any request, the visitor’s browser also sends its IP address to our server.
The badge script does not set cookies and does not try to identify the people visiting that page. If you add our badge to your site, you may want to mention it in your own privacy information.
greentracer_cookie_consent
Browser storage (localStorage)
- Purpose
- Remembers whether you accepted or rejected analytics, so we do not ask on every visit.
- Type
- Essential
- When it is set
- When you choose an option in the cookie banner.
theme
Browser storage (localStorage)
- Purpose
- Remembers whether you prefer the light or dark theme.
- Type
- Essential (preference)
- When it is set
- On your first visit, and again when you switch theme.
gt_auth_session_v1
Browser storage (localStorage)
- Purpose
- Keeps existing members signed in to their account.
- Type
- Essential
- When it is set
- Only when a member signs in. Removed when they sign out.
Google Analytics cookies (names usually begin with _ga)
Cookies, set through Google Tag Manager
- Purpose
- Help us understand how the site is used, such as which pages are visited, so we can improve it.
- Type
- Analytics (optional)
- When it is set
- Only after you choose “Accept analytics”.
Your cookie choice
You can change your choice at any time. This reopens the cookie banner so you can accept or reject analytics again. Rejecting removes the Google Analytics cookies we set. You can also clear cookies and site data in your browser settings.
How long we keep data
- Check results and report history are kept so that reports and badges keep working. They stay until they are removed, for example at the request of the website’s owner.
- Email addresses are kept until you ask us to remove them, or until we no longer need them to send your report or the updates you asked for.
- Badge records are kept while the badge is in use and needed to show where it is installed.
- Member account details are kept while the account is active and as long as we need them afterwards to meet legal obligations.
- Settings stored in your browser stay there until you clear them.
Our legal reasons
UK data protection law requires us to have a lawful reason for using personal data. Ours are:
- Legitimate interests: to run checks, publish reports, operate badges and keep the service secure and working.
- Your request: to send you the report you asked for, and to provide member accounts.
- Consent: for update emails and for analytics. You can withdraw consent at any time.
Your rights
Under UK GDPR you have the right to:
- ask for a copy of the personal data we hold about you;
- ask us to correct data that is wrong;
- ask us to delete your data;
- ask us to limit how we use your data, or object to how we use it;
- ask for your data in a format you can take elsewhere, where this applies;
- withdraw consent at any time, for example to stop update emails or analytics.
To use any of these rights, email support@buzzboost.co.uk. To be removed from our email list, just ask at the same address. We may need to confirm who you are before acting on a request.
If you are unhappy with how we have handled your data, please tell us first so we can try to put it right. You can also complain to the Information Commissioner’s Office (ICO) at ico.org.uk.
Changes to this policy
We will update this page if the way we handle data changes, for example if we add new features. The date at the top shows when it was last updated.
Contact us
Privacy questions and requests: support@buzzboost.co.uk.
Anything else: support@buzzboost.co.uk.
If your question is about a particular report, please include its link so we can find it quickly. See also our terms of use.