Cookie policy
Cookies are small files a site stores in your browser. We use a few, and analytics and advertising cookies stay off until you opt in. See our privacy policy for the wider picture.
Your choice comes first
When you first visit, we ask what you allow. Only strictly necessary cookies are set before you choose. Nothing for analytics or advertising is loaded until you opt in, and you can change your mind at any time.
Cookies we use
| Name | Category | Purpose | Provider | Expiry |
|---|---|---|---|---|
zds_consent | Necessary | Remembers your cookie preferences so we do not ask again. | This site | 6 months |
zds-theme | Necessary | Remembers light or dark theme. Stored in your browser (local storage), not sent to us. | This site | Until cleared |
zds_assessment_attribution_v1 | Analytics | Keeps bounded campaign source, medium, campaign, and page variant values for the current browser session and carries those fields into the assessment app. Stored and passed only after you opt in, without click IDs, visitor details, or referrer paths. | This site (session storage) | Browser session |
_ga, _ga_* | Analytics | Distinguishes visitors and measures site usage. Set only after you opt in. | Google Analytics | Up to 2 years |
_gid | Analytics | Distinguishes visitors over a short window. Set only after you opt in. | Google Analytics | 24 hours |
_fbp | Advertising | Identifies a browser so we can measure our Meta ad campaigns and show ads to people who already visited the site. The Meta Pixel is not loaded at all until you opt in. | Meta | 3 months |
_fbc | Advertising | Records the Meta ad click that brought you here, so a later enquiry can be attributed to the right campaign. Only set if you arrive from a Meta ad and have opted in. | Meta | 3 months |
Other Google Ads / Meta cookies | Advertising | Measures and improves ad campaigns. Set only after you opt in, and only while those tools are active. | Google, Meta | Varies |
Managing or withdrawing consent
Use the control above (also available from the footer) to review or change your choices. You can also clear cookies in your browser settings, in which case we will ask again on your next visit.
Turning advertising off stops the Meta Pixel from sending anything further and deletes the
_fbp and _fbc cookies it had set. The pixel never runs at all on our
assessment pages, whatever you choose here.
Changes to this policy
We may update this policy as the site or our tools change. The date at the top reflects the latest version.