Cookie Policy

Last updated: 10 January 2026

Cookie Summary

We use cookies to make our website work and to understand how you use it. You can control non-essential cookies through our cookie settings.

Essential
Always on
Analytics
Optional
Functional
Optional
Marketing
Optional

1. What Are Cookies?

Cookies are small text files that are placed on your device when you visit a website. They are widely used to make websites work more efficiently and to provide information to website owners.

This Cookie Policy explains what cookies are, how we use them, and your choices regarding cookies. This policy complies with the Privacy and Electronic Communications Regulations (PECR) and UK GDPR.

2. Types of Cookies We Use

2.1 Essential Cookies (Strictly Necessary)

These cookies are necessary for the website to function and cannot be switched off. They are usually set in response to actions you take, such as logging in or filling in forms.

Cookie NamePurposeDuration
session_idMaintains your login sessionSession
csrf_tokenSecurity - prevents cross-site request forgerySession
cookie_consentStores your cookie preferences1 year
auth_tokenAuthentication token for logged-in users30 days

2.2 Analytics Cookies

These cookies help us understand how visitors interact with our website by collecting and reporting information anonymously. They are only set when you accept the Analytics category in the cookie banner.

Cookie NameProviderPurposeDuration
ph_*PostHogDistinguishes users for analytics1 year
__ph_opt_in_out_*PostHogRecords your analytics opt-in/out choice1 year

2.3 Functional Cookies

These cookies enable enhanced functionality and personalization, such as remembering your preferences and settings.

Cookie NamePurposeDuration
user_preferencesStores your display preferences1 year
calculator_stateRemembers your last calculation inputs30 days
themeLight/dark mode preference1 year

2.4 Marketing Cookies

We do not currently use any third-party marketing or advertising cookies. If we introduce marketing cookies in the future, we will update this policy and request your consent before setting them.

2.5 Analytics & Session Replay

We use PostHog for privacy-focused analytics and optional session replay. Analytics/session cookies are only set when you accept the Analytics category in the banner or when Do Not Track is off. Session replay recordings are limited to 30 days and exclude sensitive fields where possible.

2.6 Optional Rewarded Ads

Free users may choose to watch an optional rewarded ad to unlock extra usage. No ad or marketing cookies are set unless you start the rewarded ad experience.

3. How to Control Cookies

3.1 Cookie Consent Banner

When you first visit our website, you will see a cookie consent banner. You can:

  • Accept All: Enable all cookies
  • Reject Non-Essential: Only essential cookies will be used
  • Customize: Choose which categories of cookies to allow

3.2 Changing Your Preferences

You can change your cookie preferences at any time by clicking the "Cookie Settings" link in the footer of any page, or by clearing your browser cookies and revisiting our site.

3.3 Browser Settings

Most web browsers allow you to control cookies through their settings. You can:

  • Block all cookies
  • Block third-party cookies only
  • Delete cookies when you close your browser
  • Browse in "private" or "incognito" mode

Note that blocking all cookies may affect the functionality of our website.

Links to browser cookie settings:

4. Third-Party Cookies

Some cookies are placed by third-party services that appear on our pages. We do not control these cookies. The third parties include:

  • PostHog: For privacy-focused website analytics
  • Stripe: For payment processing
  • AWS Cognito: For authentication

Please refer to the privacy policies of these third parties for more information about how they use cookies.

5. Local Storage and Similar Technologies

In addition to cookies, we may use other technologies to store information locally on your device:

  • Local Storage: Used to store your saved calculation scenarios
  • Session Storage: Used to maintain state during your session

These technologies are subject to the same consent requirements as cookies.

6. Do Not Track

We respect the "Do Not Track" (DNT) browser setting. When DNT is enabled, our analytics tools will not load and no tracking cookies will be set, regardless of your cookie consent preferences. You can also use our cookie consent tools to control tracking independently of DNT.

7. Updates to This Policy

We may update this Cookie Policy from time to time. Any changes will be posted on this page with an updated revision date.

8. Contact Us

If you have questions about our use of cookies, please contact us: