What is the onesignal-notification-prompt cookie?
onesignal-notification-prompt is not a classic HTTP cookie but a value stored in the browser's localStorage, generated by the OneSignal script embedded on a website (its web push SDK). It appears as soon as a visitor lands on a page where OneSignal is active and configured to show a permission prompt.
It is set by the third-party provider OneSignal, but under the domain of the website using it, through the JavaScript snippet loaded by the site owner.
What data it stores
It stores information about the state and history of the push notification permission prompt: whether it was shown, whether it was dismissed or accepted, and possibly the timestamp of the last display, used to control how often it reappears.
The exact value format varies by OneSignal SDK version and is not documented in detail publicly. The data generally stays local to the browser, but OneSignal may correlate it with a device identifier sent to its infrastructure for managing push subscriptions.
What it is used for
Its main purpose is functional: avoiding repeated, annoying push permission requests to the same visitor who has already responded (accepted or declined).
For site owners, this improves user experience and increases the chance the prompt appears at a more suitable moment, while also respecting browser rules that limit how often permission prompts can be re-triggered.
Does it require consent?
In CookieFix's classification, onesignal-notification-prompt falls under preferences (functional). Although technically a localStorage entry rather than a cookie, the ePrivacy Directive (transposed in Romania via Law 506/2004) and the GDPR apply equally to any storage technology on a user's device.
Since it relates to a non-essential feature (push notifications, not core site functionality), it requires the visitor's prior consent before being set. Site owners must declare it explicitly in their cookie policy and configure the consent banner so the OneSignal script only loads after acceptance.
How to block or delete onesignal-notification-prompt
A visitor can delete or block this value from browser settings, under site data (Site Settings / Storage), by clearing stored data for that domain, or by blocking push notification permissions for that site directly in the browser.
- From the browser: clear localStorage for the domain or disable the notification permission
- From site settings: withdraw consent via the cookie preferences panel, if the site offers one
For site owners, a consent management platform (CMP) like CookieFix can automatically block the OneSignal script from loading until the visitor consents to the preferences category, preventing this entry from being set prematurely.
Frequently asked questions
It's a localStorage entry, not a classic HTTP cookie, but legally (under ePrivacy/GDPR) it's treated the same way, as a device storage technology.
Yes, since it's classified as preferences/functional and tied to a non-essential feature (push notifications), it requires the visitor's prior consent.
The site and the OneSignal script may show the notification permission prompt again on the next visit.
By using a CMP that delays loading the OneSignal script until the visitor accepts the preferences category in the consent banner.