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Nullgen AI Blocker

Block AI on every device, from the prompt box to the app

Our browser extension stops AI prompts before they are ever sent. On phones and desktops, we stop known AI apps and sites from loading at all. One suite for every device your family, classroom, or company uses.

Start a free trial

AI blocker suite for browsers, desktop, and mobile

  • Blocks prompts and AI apps
  • 100% on-device processing

One suite, every device

The browser extension, plus apps for phones and desktops

The extension stops AI prompts in the browser. The apps stop known AI apps and sites from loading on phones and desktops. One Pro account manages all of them.

Who it’s for

One suite, three very different reasons to use it

Prompt blocking in the browser is completely free. The Pro plans add the mobile and desktop apps, plus admin controls for parents, teachers, and organizations.

Two kinds of blocking

The right block for each device

In the browser, the extension blocks the prompt itself: the rest of the site keeps working, and new assistants are caught automatically. On phones, tablets, and desktop apps there is no prompt box to hook, so the apps block the AI destination instead. One account runs both.

In the browser: block the prompt

The extension recognizes AI prompt boxes on any website and stops typing and pasting into them.

Chrome, Edge, Firefox, and Safari

  • Keeps search, research, and every other site working
  • Covers new assistants without a site list
How the extension works

On phones and desktops: block the destination

The apps stop known AI apps and websites from loading on the whole device, in every browser and in the apps themselves.

iPhone, iPad, Android, macOS, and Windows

  • Reaches AI apps, not just browser tabs
  • A list of 100+ AI destinations that keeps growing
How the mobile app works

  • Runs on device

    Detection and blocking happen on the device itself. Prompts and browsing are never uploaded to us.

  • One account, every device

    One Nullgen Pro account covers the extension, the phone app, and the desktop agents.

  • Always up to date

    New AI tools are covered automatically, in the browser and in the apps.

What the free extension does today

One job, done well: text never makes it into an AI prompt box.

  • Blocks prompt input

    Typing and pasting into AI chat inputs is prevented, on any website and in any kind of chat box.

  • Your privacy, protected

    Nothing you type is uploaded or stored. Detection runs entirely in your browser, so your data always stays in your computer.

  • Detection is completely automatic

    It spots AI chat boxes wherever they appear — including brand-new assistants you have never heard of.

  • One-minute setup

    Install the extension and it starts working immediately. No proxy, no certificate, no network changes.

How the extension works

  1. 01

    Install the extension

    Add it from your browser’s store on any computer you want covered.

  2. 02

    Prompts are recognized

    As pages load, the extension identifies inputs that behave like AI chat prompts.

  3. 03

    Input is blocked

    Text entry into those fields stops working, so nothing can be submitted to the model.

Pro

Centralized management

Everything in the free extension stays free. Pro is for people who need to manage more than their own browser, and it includes the mobile and desktop apps.

Start a free trial

  • Users and devices

    Add the users you manage, choose their approvers, and enroll their computers, phones, and tablets.

  • Access requests

    Users can ask for AI access. Approvers can approve or deny requests.

  • Real-time policy sync

    Policy changes reach enrolled browsers and apps as they are saved, without waiting for a restart.

  • Deploy and pin

    Force-install on managed browsers and pin it so it cannot be turned off or uninstalled.

Common questions

  • Is the free version limited or a trial?

    Neither. Prompt blocking in the browser is the free product and stays free. Pro adds the admin portal, fleet management, and the mobile and desktop apps on top.

  • Do you see what people type?

    No. Detection runs in the browser and prompt text is not sent to us. The apps block on the device and never send what you browse to us. The free extension has no account, so there is nothing tied to you.

  • Does it only block ChatGPT?

    No. The extension finds AI prompt boxes on any website, including new assistants, and leaves the rest of the page usable. The apps block a growing list of known AI apps and sites on the whole device.

  • Does it work on phones and tablets?

    Yes. The Nullgen app for iPhone and iPad blocks known AI apps and websites on the device and links to the same Pro dashboard as the extension. An Android app is coming soon.

  • What about desktop AI apps, like ChatGPT for Mac or Windows?

    The browser extension only sees the browser. macOS and Windows agents that block known AI apps and sites across the whole computer are coming soon, and they will be included with Nullgen Pro.

  • Which languages are supported?

    Only English websites are supported today. We plan to support other languages in the future.

  • Can it be uninstalled by the person using the device?

    Yes. The browser extension, the mobile app, and the desktop app can all be uninstalled. Nullgen Pro adds enforcement to pin the extension and apps, alongside OS-level family and enterprise controls.

Start with the free extension

It takes a minute to install with no commitments. Add the iPhone and iPad app with Pro, and get Android, macOS, and Windows when they ship.

Download Free Extension