Install @t Filter

Pick the device to protect and follow the steps. You need an installation code: it links the device to your household.

Locked Screen Time (adults and children, no paid account)

A Screen Time passcode held by someone else (a witness or parent) stops the settings below from being undone without them. That person chooses and types the passcode on the device: AT Filter never sees it and never receives it. Setting names follow Apple's help pages; wording may differ slightly between versions.

Install the AT Filter profile first (the "Profile" button in the steps above), then follow this guide.

Mac (macOS 15, 26)

Apple menu → System Settings → Screen Time: turn it on. Have the witness or parent create the passcode and type it themselves (the passcode option is in the Screen Time options; exact label not verified).
Screen Time → Content & Privacy: turn it on.
App Store, Media, Web, & Games → Safari: Limit Adult Websites.
Store Restrictions, "Allowed on iOS": Installing Apps, Deleting Apps. Preference Restrictions: Passcode, Account. Apple says these options apply to iOS and iPadOS devices, not to the Mac.

What this lock does not guarantee

The Apple pages consulted do not say Screen Time prevents removing a configuration profile or a VPN. Treat the AT Filter profile as removable: only a supervised device makes it non-removable (see the stronger protection).
The lock only works while the passcode stays secret. Anyone who knows it can undo everything, and AT Filter can neither read nor check it.
On Mac, the pages consulted describe install, delete, passcode and account blocks for iOS and iPadOS devices: do not assume a Mac is locked the same way.
Other iOS or macOS versions may rename these settings. If in doubt, the console shows the device's real state.

Apple sources

Mac

Create a “standard” macOS account for the protected user. Keep the administrator password to yourself: without it, the profile cannot be removed.
On this Mac, download the AT Filter profile: it closes adult sites across the whole Mac (safe DNS), closes private browsing in Safari, Chrome, Edge, Brave and Firefox, and enforces SafeSearch. Download the AT Filter profile
Then, the same way, the second profile: it blocks private browsing and enforces SafeSearch in Chrome, Edge, Brave and Firefox. If it is refused, the essentials stay active. Download the browsers profile
Open System Settings → Privacy & Security → Profiles, choose “AT Filter” then “Install” (administrator password). Then fully quit any open browsers (Cmd+Q) and reopen them: private browsing is then closed (check chrome://policy).
For the whitelist and image analysis, also install the AT Filter extension in Chrome and connect it with this code:
YOUR-CODE

In your browser

The AT Filter extension blocks adult sites and enforces SafeSearch in the browser, even without the app. Pick yours.

Finally: check

When the device is linked, it shows in your console as "Filter on". Tick as you go:

The AT Filter app is installed and the install code entered.
The filter is on (VPN request accepted).
Device administrator and Accessibility are enabled.
The device appears in the management console, status "Filter on".

Open the console to check

Get my installation code

Enter the email address of your @t Filter account: we send you a code valid for 2 hours.

No account yet? Create my household