What is the 1P_JAR cookie?
1P_JAR is a third-party HTTP cookie belonging to Google, usually visible on the google.com domain. Its name, according to publicly available Google explanations, is derived from "Just A Reminder" — an internal label Google uses to identify the cookie.
On Romanian websites scanned by CookieFix, this cookie typically appears as a result of integrating Google services — for example Google Ads, Google Analytics, Google Maps, or other widgets loading resources from Google domains. It is not set directly by the site's own code, but by Google scripts loaded on the page.
What data it stores
1P_JAR does not store directly identifying information (name, email), but rather a technical identifier associated with the browsing session on Google services. According to Google's public cookie documentation, this cookie is used to maintain preferences and to measure interactions with advertisements.
The exact value format is not documented in detail by Google and may vary; the collected data is sent to Google's servers, where it is aggregated for advertising reporting and traffic analysis.
What it is used for
The main purpose of 1P_JAR is advertising-related: Google uses it to support the measurement of ad campaign effectiveness (for example, correlating ad impressions with subsequent visits to websites or to google.com) and, potentially, to retain certain search-result preferences.
For the site administrator, this cookie offers no direct control — the site indirectly benefits from aggregated data in Google Ads/Analytics reports, but responsibility for informing visitors remains with the site that embeds the Google service.
Does it require consent?
Under CookieFix's classification, 1P_JAR falls under the marketing category (advertising/tracking). As it is not essential for the website's functioning, placing it requires the user's prior consent, in line with the ePrivacy Directive (2002/58/EC, transposed in Romania via Law 506/2004) and GDPR data-processing principles.
- The site administrator must block the Google scripts that generate this cookie until explicit consent is obtained.
- The cookie must be listed in the site's cookie policy, along with its category, provider and duration.
- Refusing consent must not block access to the website's core content.
How to block or delete 1P_JAR
A visitor can delete or block 1P_JAR directly from browser settings (Chrome, Firefox, Edge, Safari), from the cookie-management section for the google.com domain, or by using ad-tracking blocking extensions. Google also offers ad-personalization settings in a user's own Google account, where interest-based advertising can be restricted.
For site administrators, the most practical solution is using a Consent Management Platform such as CookieFix, which automatically blocks the Google scripts that place this cookie until the visitor gives consent for the marketing category, helping keep the site aligned with legal requirements.
Frequently asked questions
It's an advertising cookie set by Google on the google.com domain, used to measure interactions with ads and, potentially, to retain certain preferences.
It doesn't contain publicly documented sensitive data, but it is a tracking cookie used for advertising purposes, which is why it requires user consent.
The typical observed duration is around one month, after which the cookie expires or is renewed on a new visit to Google services.
Yes, as a third-party marketing cookie it must be listed in the cookie policy along with its purpose, provider and duration, and its placement requires prior consent.