What is the theme cookie?
„theme” is a generic cookie name found across a wide range of websites, WordPress themes, e-commerce platforms and web apps built on various frameworks — hence the „Various” provider classification. It is not tied to a single vendor, but to a common feature: storing a visitor's visual theme preference.
It is typically set as soon as a visitor manually switches the site's appearance (for example, via a light/dark toggle), or in some implementations is set automatically on first visit to record the default theme.
What data it stores
The stored value is usually a simple identifier for the selected theme (for example „light”, „dark”, or the name of a colour scheme). The exact format varies by site, depending on implementation.
The data stays stored locally in the visitor's browser and is sent to the setting site's domain on subsequent requests, so the page can be rendered with the correct appearance.
What it is used for
The cookie serves a purely visual purpose: it lets the site remember the visitor's appearance preference across sessions, so they don't need to reset the theme on every visit.
For the site owner, this type of cookie improves browsing comfort and can reduce drop-off caused by an uncomfortable interface, such as a bright layout showing up at night.
Does it require consent?
CookieFix classifies „theme” as a preferences (functional) cookie. Under the ePrivacy Directive (2002/58/EC, transposed in Romania via Law 506/2004) and GDPR, preference cookies are generally not strictly necessary for the site's core technical function, so prior consent from the visitor is required, typically via a banner.
- Declare the cookie in your cookie policy, with accurate purpose, duration and category.
- Do not set it by default before consent, unless your implementation treats it as strictly necessary (e.g. accessibility only, with no tracking).
- Periodically check that the theme/plugin in use only sets this cookie for visual preference and not for additional profiling.
How to block or delete theme
Visitors can delete or block „theme” from their browser settings (Chrome, Firefox, Edge, Safari), either by clearing cookies for that domain or disabling cookies entirely for that site. Deleting it usually restores the site's default theme.
For site owners, a CMP such as CookieFix can automatically block the script that sets this preference cookie until the visitor gives consent through the banner, helping maintain the control required under GDPR/ePrivacy.
Frequently asked questions
It remembers a visitor's visual preference on a site, such as light or dark mode, so the chosen appearance is kept on later visits.
Usually yes, since it is classified as a preferences/functional cookie and is not strictly necessary for the site's core technical function under GDPR and the ePrivacy rules.
Its typical duration is 1 year, though this can vary by site or platform.
You can clear the site's cookies from your browser's privacy settings; the site will then revert to its default theme on your next visit.