CookieYes Validator Troubleshooting Guide
Last updated on May 21, 2026
1. Why are some listed cookies not showing up in my browser?
These cookies are in your CookieYes list but the extension shows them as Not detected.
Have you accepted cookies for that category?
This is the most common reason. CookieYes blocks non-necessary cookies until the visitor gives consent. If you haven’t accepted Analytics cookies, for example, Analytics cookies will not be set in the browser — and that is correct behaviour, not a problem. Accept all cookie categories and re-run the extension to get a complete picture.
Did the cookie require a specific action to trigger?
Some cookies are only set after a user does something on the page — scrolling, playing a video, clicking a button, or interacting with a widget. If you opened the extension immediately after the page loaded, those cookies may not have fired yet. Try interacting with the page first, then refresh the extension scan.
Are you on the right page?
Some cookies are only set on specific pages of your site. A checkout cookie, for example, will only appear on the checkout page. To find out which URL a cookie was discovered on, go to Cookie Manager → Scan History → More info against your most recent scan. This shows you exactly which cookies were identified on which pages. Navigate to that specific URL and re-run the extension there for an accurate result.
Has the third-party script been removed or updated since the last scan?
If a tool you previously used has been removed from your site, or if a third party has renamed or changed their cookie, the old listed name will no longer match anything in the browser. Re-scan your site in CookieYes to update the list to reflect the current state of your site.
Did the browser itself block the cookie?
Modern browsers apply their own tracking protection independently of CookieYes. Safari’s Intelligent Tracking Prevention and Chrome’s Privacy Sandbox can block certain third-party cookies regardless of consent settings. If this is the case, no action is needed — CookieYes is functioning correctly.
Is the cookie set with invalid attributes?
If a cookie is configured with SameSite=None but without the Secure flag, modern browsers will silently reject it — it will never appear in the browser even if the script attempts to set it. This is a configuration issue on the third-party’s side, not a CookieYes issue.
2. Why are some browser cookies not in my CookieYes list?
These cookies are present in the browser but have no matching entry in your listed cookie data.
Have you re-scanned your site recently?
The most common reason. If a new third-party script was added to your site after your last CookieYes scan, the cookies it sets will not be in your list yet. Re-scan your site and CookieYes will automatically detect and add the new cookies.
Was this cookie triggered by a specific user interaction?
CookieYes’s scanner simulates basic interactions like page scrolls and clicks, but it cannot replicate every possible user flow. Cookies that only fire after a multi-step interaction — completing a form, watching a video to the end, or navigating through a specific sequence of pages — may never be picked up by the scanner. If you know what the cookie is, you can add it manually to your CookieYes list.
Could this cookie be region-specific?
CookieYes’s scanner runs from a fixed server location. Some third-party tools serve different cookies depending on the visitor’s geographic region. If the scanner’s IP was in a different region than your typical users, it may not have encountered those region-specific cookies during the scan. Adding them manually is the recommended fix.
Is this cookie only set after a user logs in or completes a transaction?
Cookies set after authentication, form submissions, or checkout flows are not visible to a standard scan because the scanner does not log into your site. If your site sets cookies behind a login or a specific user journey, use CookieYes’s Scan Behind Login feature to let the scanner discover those cookies properly.
→ Learn how to set up Scan Behind Login
Is this an A/B testing or a personalisation cookie?
Some tools only set cookies for certain user segments or test variants. The scanner may have been assigned to a different segment than your current browser session, meaning it never encountered that cookie during the scan. Add it manually if you can identify which tool is setting it.
If your issue isn’t covered here, please contact our support team and we’ll be happy to help.
