What is the mage-cache-sessid cookie?
mage-cache-sessid is a cookie generated automatically by Magento (Adobe Commerce / Magento Open Source), the e-commerce platform the website runs on. It is part of Magento's internal page-cache management system, alongside related cookies such as mage-cache-storage and mage-cache-storage-section-invalidation.
It appears on the first page load of the online store, whether the visitor is logged in or browsing as a guest. It is set by the storefront theme's front-end code, not by a third-party service.
What data it stores
The cookie does not store personal data; it holds a technical flag used by Magento's scripts to decide whether the browser's local cache (typically stored in localStorage, tracked via mage-cache-storage and mage-cache-storage-section-invalidation) needs to be cleared or resynced.
The value is an internal identifier generated by Magento, with no publicly standardized format; it is not sent to external services, only read by the store's own JavaScript on the same domain.
What it is used for
Its main role is to keep the data shown to the visitor (e.g. shopping cart, personalized pricing, content blocks) consistent with the browser's local cache, preventing stale information from being displayed after an action such as adding a product to the cart.
For the store owner, this cookie supports the correct operation of Magento's caching mechanism (Full Page Cache combined with private section caching), which is important for site performance.
Does it require consent?
In CookieFix's classification, mage-cache-sessid falls under the necessary (strictly necessary) category. Since it is indispensable to the basic functioning of a Magento store (correct handling of the browsing session and cart), it does not fall under the prior-consent requirement of the ePrivacy Directive (as transposed in Romania by Law 506/2004).
Site owners should still list it in their cookie policy, along with its purpose and duration, in line with the transparency obligations under GDPR and national electronic communications law.
How to block or delete mage-cache-sessid
A visitor can delete or block this cookie from browser settings (Chrome, Firefox, Edge, Safari – per-site cookie management), though blocking it may affect how the shopping cart or personalized content displays on that site.
- Manual deletion: through the browser's cookie manager, by searching for the store's domain.
- Private/incognito browsing: the cookie is created temporarily and disappears when the session ends.
Because it is strictly necessary, a CMP like CookieFix does not block it before consent — it is automatically classified as necessary and listed transparently in the cookie policy generated for the site.
Frequently asked questions
It is a technical cookie set by the Magento platform to correctly manage the page cache shown to visitors of an online store.
It is set directly by the front-end code of the Magento platform the site runs on, not by an external third-party service.
No, it is classified as strictly necessary because it supports core store functionality (cart, session), but it should still be listed in the cookie policy.
The shopping cart contents or personalized content on the site may not update or display correctly.