60-second summary
- Browser push alerts can appear even when the website is closed.
- Permission and compatible device settings are required.
- Delivery depends on the browser, operating system, internet connection and notification settings.
- Browser push supplements—but does not replace—official emergency alerts.
Direct answer: Browser push alerts are notifications sent through a supported web browser after the user gives permission. They can appear even when the website is not open, but delivery still depends on the device, browser, operating system, internet connection and notification settings. They are not the same as government cell-broadcast alerts or SMS.
The basic process
- You open a website in a supported browser.
- The site asks for notification permission.
- Your browser creates a subscription linked to that browser profile and device.
- When the service sends an alert, a push provider routes it to the browser.
- The operating system displays the notification if settings and connectivity allow it.
Browser push, SMS and cell broadcast
| Method | What identifies the recipient | Key point |
|---|---|---|
| Browser push | A browser/device subscription | Requires permission and compatible settings. |
| SMS | A mobile telephone number | Sent through the mobile messaging network. |
| Cell broadcast | Compatible phones connected to cells in an affected area | Used by some official national emergency-alert systems. |
Why a push alert might not appear
- Notifications are blocked for the website, browser or operating system.
- The browser profile was cleared or replaced.
- The device has no connection or is in a restrictive power mode.
- Focus, Do Not Disturb or notification-summary settings suppress it.
- The browser or operating system is unsupported or outdated.
Privacy and device management
A responsible service should explain what information is collected, how subscriptions are linked, how to revoke permission and how to remove old devices. Users should periodically test their setup and remove browser profiles they no longer use.
Frequently asked questions
Do I need to keep the website open?
Usually no. Once permission and the browser subscription are active, notifications can arrive while the site is closed.
Is browser push guaranteed?
No. Delivery depends on several external systems and device settings, so it should supplement—not replace—official warning channels.
Does a browser notification reveal my phone number?
Browser push normally uses a device/browser subscription rather than a telephone number.
Primary sources and further reading
This guide is general information. For a live emergency, use the current instructions from the relevant authority.