How Skinli works

You take one photo of your face, or upload one. It is sent to an outside AI service with a fixed set of rules. The rules tell it to look only at the skin, and never to say anything about your age, race, identity, looks, or health beyond acne. It sends back only these facts:

Is the photo clear?

Yes or no. No means it cannot see the skin well: no face, more than one face, too small, too dark, too blurry, a filter, heavy makeup, or most of the face covered. Then it writes one short tip on how to take it again.

Main kind of pimples

Blackheads and whiteheads, red pimples, pimples with pus, or a mix.

How many, as a group

Under 10, 10 to 20, or more than 20.

How many, as a number

Its best guess, from 0 to 60.

Marks

None, flat red or brown marks, or dents and scars.

Warning signs

Deep sore lumps, 10 or more pimples with pus, or scars. The list can be empty.

Where

Any of: forehead, nose, cheeks, chin, jaw.

What it sees

Three short sentences in simple words, about things it can see.

If the photo is not clear, you are asked to take it again, with the reason. After two unclear photos, you can answer a few questions about your pimples instead. The free routine builder uses those same questions with no photo at all.

What happens to your photo is on the privacy page.

Then you answer what a photo cannot see: whether you have used acne products before, which ones, and whether new creams sting you. If you have not used any, you get two questions. If you have, you get three.

The score is a simple count, not a medical grade. These are the exact rules:

1. Everyone starts at 100. A higher score means clearer skin.
2. Each pimple takes off 2 points, up to 60 points. No pimples takes off nothing. 5 pimples take off 10. 30 or more take off 60.
3. The pimple number is the AI estimate from your photo. It can be wrong. It stays inside the group the AI picked: under 10, 10 to 20, or more than 20.
4. If there is no number from a photo, a few pimples counts as 5, some counts as 15, and a lot counts as 30.
5. Flat red or brown marks take off 10 points. Dents or scars take off 20 points.
6. Each warning sign takes off 10 more points. The signs are deep sore lumps, 10 or more pimples with pus, and scars.
7. The lowest score is 10.

The plan is written by fixed rules in Skinli's own code, not by the AI. It is a guideline plan for everyday acne, adjusted for how sensitive your skin is, what you already tried, and whether you need a doctor.

• Everyone without a doctor's medicine gets the same two gels at night: benzoyl peroxide 2.5% and adapalene 0.1%. The photo does not pick a different medicine.
• The gels start every other night for 2 weeks, then every night. If you said creams sting you a lot, it starts gentler: moisturizer goes on first, the gels come off after 1 hour for the first 2 weeks, and every night starts in week 5.
• Every plan has the same base: face wash and moisturizer morning and night, and sunscreen SPF 30 every morning.
• If you said a doctor gave you acne medicine, the plan tells you to keep using it, and to ask your doctor before you add anything.
• If you use salicylic acid, the plan asks you to stop it. The adapalene label says sore, red, or dry skin is more likely when you use more than one acne medicine. The plan already uses two.
• If the photo or your answers show deep sore lumps, dents or scars, more than 20 pimples, or many pimples with pus, a See a doctor first box goes at the top. You still get the plan, to start while you wait.
• If there are flat red or brown marks and you pick the 12 week plan, a mark cream (azelaic acid 10%) is added from week 5.
• If you already tried both gels, the plan asks if you used them together every night for 12 weeks. If yes, it tells you to see a doctor.

Give the plan 12 weeks before you judge it. The American Academy of Dermatology says it takes at least 6 to 8 weeks before you start to see fewer pimples. The adapalene label says results can take up to 3 months.

Where the rules come from

• Acne vulgaris: management (NG198) (NICE)Lists adapalene with benzoyl peroxide, once each evening, as a first choice for acne of any severity.
• Guidelines of care for the management of acne vulgaris (2024) (Journal of the American Academy of Dermatology)Makes strong recommendations for benzoyl peroxide and for topical retinoids such as adapalene.
• Label: adapalene gel 0.1% (DailyMed)How to use it, the early worsening, the irritation warning, and the time to see results.
• Acne: treatment (NHS)When to see a doctor.

• It has not been tested on different skin tones, so nobody knows yet how well it reads each one.
• Light changes what a photo shows. The AI is told to reject photos that are too dark or too blurry, but a photo can pass and still hide some bumps.
• Makeup and filters hide bumps and color. The AI is told to reject a photo when a filter or heavy makeup hides the skin. Light makeup can still hide some.
• It sees only the surface. It cannot see what is under the skin, feel how sore a bump is, or know your health history.
• It cannot diagnose acne or any other skin problem. Only a doctor can do that.

We do not know yet. Skinli has not run an accuracy test. Nobody has compared its pimple count with a dermatologist's count, so there is no accuracy number. Treat the count as a rough guide, and take your photos the same way each time so they are easier to compare.