Legal

Privacy Policy

Effective October 7, 2026

This policy explains what the HaltBlock browser extension and app do with data. It applies to HaltBlock for Chrome and Edge, HaltBlock for Safari, and this website. HaltBlock was previously called Blok.

The short version: HaltBlock has no accounts, blocks ads on your device, and only sends data to the services listed below, for the reasons listed below.

What stays on your device

HaltBlock keeps the following in your browser's extension storage. It isn't sent anywhere:

• Settings, such as which features are on, your label sensitivity, and your own hiding rules.
• Paused sites: the sites where you turned HaltBlock off.
• Your votes: whether you marked a label as correct or not, so HaltBlock remembers your answer on this device. HaltBlock also uses your votes to adjust its label sensitivity for you.
• Counts of ads blocked and items labeled.
• A cache of AI scores, stored under one-way fingerprints of the content, so the same item isn't checked twice.
• A random install ID. HaltBlock creates it the first time you vote. It isn't linked to your name, email, or any account.
• Your Pro license key and its activation ID, if you entered one (Chrome and Edge).
• The latest ad-hiding rule list downloaded from our server (see below).

Ad blocking itself happens inside your browser: HaltBlock uses the browser's built-in blocking with filter lists that ship with the extension. Text analysis for AI labels also runs on your device; the text you read is never uploaded for analysis.

If you turn on “Show YouTube ads on channels I'm subscribed to” (off by default), HaltBlock saves the IDs of the YouTube channels you're subscribed to in youtube.com's storage in your browser, so it can recognize those channels. For those channels' videos, YouTube's normal ad measurement runs as it would without HaltBlock.

Feedback votes

AI labels (a HaltBlock Pro feature) have 👍 and 👎 buttons. When you tap one, HaltBlock sends this to our server, which runs on Supabase:

• a one-way fingerprint (SHA-256 hash) of the item: of the text for posts and comments, of the image's web address for images, or of the YouTube video ID for videos. A fingerprint can't be turned back into the content;
• the content type (text, image or video);
• the domain of the site you were on, for example reddit.com, not the full page address;
• your vote (AI or not AI);
• HaltBlock's score for the item and the detection version;
• your random install ID;
• the platform (Chrome, Edge, iOS or macOS) and HaltBlock's version number.

Samples are only sent if you opt in. If you turn on “Share flagged samples to improve HaltBlock” (off by default), your vote also includes the item itself: up to 2,000 characters of the text, the image's web address, or the YouTube video link. You can turn this off at any time in HaltBlock's settings.

Community vote lookups

To show how other people voted, HaltBlock sends our Supabase server the fingerprints (hashes) of items it's checking, and gets back vote counts. Only the fingerprints are sent, not the content and not the page address. This only happens when AI labels are on (HaltBlock Pro).

Image checks

Many AI images carry a signature saying they were AI-generated (Content Credentials or similar metadata). To read it, HaltBlock may download images from the pages you visit, including YouTube thumbnails, directly from the site that hosts them. These downloads are made without your cookies. The site sees an ordinary image request, just as when your browser shows the image. The image is checked on your device and isn't sent to us. This only happens when AI image or video labels are on (HaltBlock Pro).

Filter rule updates

Once a day, and when the browser starts, HaltBlock downloads an updated list of ad-hiding rules from our server. The list is data (JSON) only, never code. The download doesn't include anything about you or your browsing.

SponsorBlock

If you have HaltBlock Pro and “Skip YouTube sponsor segments” is on (it's on by default for Pro), HaltBlock sends the ID of the YouTube video you're watching to SponsorBlock (sponsor.ajay.app) to find the sponsor reads to skip. SponsorBlock is a third-party service with its own privacy policy. HaltBlock doesn't send it anything else.

To stop this, turn off “Skip YouTube sponsor segments” in HaltBlock's settings: the settings page in Chrome and Edge, or the HaltBlock app on iPhone, iPad and Mac.

Payments and license keys

• Chrome and Edge: HaltBlock Pro is sold by Lemon Squeezy, which takes the payment and emails you a license key. We never see your card details. To check that your key is valid, the extension sends Lemon Squeezy the key, an activation ID, and a label naming your browser (“HaltBlock for Chrome” or “HaltBlock for Edge”). It re-checks about once a day. See Lemon Squeezy's privacy policy.
• Safari: HaltBlock Pro is bought through the App Store. Apple handles the payment, and we never see your payment details.

How we use data

We use the data above only to block ads and to improve AI detection, for example to show community votes and to tune labels. We don't sell data, don't use it for advertising, and don't share it except with the services named on this page. HaltBlock contains no ads and no analytics or tracking tools.

Services we use

• Supabase hosts our server: votes, community vote counts, the rule list and the website waitlist. See Supabase's privacy policy.
• Lemon Squeezy, for Chrome and Edge purchases and license keys.
• SponsorBlock, for sponsor segments (Pro, can be turned off).
• Apple, for Safari subscriptions.

Like any web service, these services receive your IP address when HaltBlock connects to them. Supabase keeps standard request logs, which include IP addresses, for a short time. We don't store IP addresses with votes.

How long data is kept

• On your device: until you uninstall HaltBlock or clear the extension's data.
• Votes on our server: kept to power community scores until you ask us to delete them.
• Waitlist emails: kept until HaltBlock launches on the browser you picked, or until you ask us to delete them.

Deleting your data

• On your device: uninstalling HaltBlock removes everything it stored in your browser.
• On our server: email support@haltblock.com and we'll delete your votes. Because votes aren't linked to who you are, please include your install ID. In Chrome and Edge it's shown at the bottom of HaltBlock's settings page. To remove a waitlist email, email us from that address.

Website

If you join the waitlist on this website, we store your email address so we can tell you when HaltBlock is available. The website has no ads and no analytics.

Children

HaltBlock doesn't knowingly collect personal information from anyone, including children under 13.

Changes and contact

If this policy changes, we'll update it here and change the effective date above. Questions: support@haltblock.com, or see the support page.