How it works, explained
How On Guard works, one page per question.
The walkthrough shows it. These four pages say it plainly: where detection runs, what a detection does, why there are no screenshots, and exactly what your ally receives.
Explicit content shows up, your ally knows. They learn that it happened, never what.
4 guides · Checked August 18, 2026 against the shipping app
What stays on your device, and what leaves it
Your device
What is on your screen
Frames are sampled as you scroll and browse.
On Guard engine
Classifies each frame locally. Nothing is uploaded.
A verdict
Clean, suggestive, or explicit. The frame is discarded.
Crosses the boundary
- A liveness heartbeat
- A detection event, with no content
- Your account, settings, and billing
Never crosses it
- Screenshots or frames
- URLs or browsing history
- What you were looking at
- 01
What on-device detection means
The engine runs on your Mac, Windows PC, or Android phone. It looks at what is on your screen, decides clean, suggestive, or explicit, and throws the frame away. What crosses to the internet is a heartbeat, an event, and your account. Never the picture.
4 min read
- 02
What happens on a detection
Explicit content gets a gate on your screen, a way out to something better, and one check-in text to your ally. Suggestive content gets a nudge and nothing more. Clean content gets nothing. Here is each, in order, using the real screens.
4 min read
- 03
Why we do not keep or send screenshots
Screenshot accountability captures your screen, uploads it, and gives someone a feed to review. On Guard looks at your screen on the device, in memory, discards the frame, and sends one text that says it happened. Nothing is saved and nothing is uploaded. We think that is the safer model and the more human one. Here is the reasoning.
4 min read
- 04
What your ally receives, and does not
One short text when explicit content is gated on your device. A text if defense is turned off or On Guard is uninstalled. A lapse alert if a device goes quiet. Never the site, the image, your history, or anything from the suggestive tier. Here it is, word for word.
3 min read
Prefer to see it? The scroll walkthrough runs the gate, the redirect, and the text from inside the app: Watch it work.
Questions answered
Is this the same as the how-it-works page?
No. That page is a walkthrough you scroll, from inside the app. These four pages are the plain-text answers behind it, one question each, so you can read or share exactly the part you need.
What is the shortest honest summary?
Detection runs on your device. Explicit content gets a gate, a way out, and one check-in text to your ally. Suggestive content gets a nudge and nothing else. No screenshots are kept or sent, and your ally learns that it happened, never what.
What about iPhone?
On iPhone and iPad, On Guard runs no detection engine of its own; it works through Apple's Screen Time controls. The ally check-in, account, and settings are the same everywhere.