How Skop decides

Where the facts come from

Product data comes from Open Food Facts, a public database maintained by volunteers worldwide, under the Open Database License (ODbL). It's the same data for every app that uses it — and because people write it, it is sometimes incomplete or out of date. When you photograph a label, you're improving it for everyone.

Your verdict

Skop compares a product's ingredient list against rules you chose. "Doesn't match your preferences" means exactly that — one of your rules isn't met, and Skop shows which ingredient and which rule. Skop never decides that a product is good or bad. Different rules, different verdict, same product.

When there's no ingredient list

Plenty of products have a name, a photo and a nutrition table, but nobody has typed in the ingredients yet. For a narrow set of those — plain fruit, plain vegetables, plain nuts, plain fish, plain meat, eggs, plain rice, plain tea and coffee — the product is its own ingredient, so Skop can answer a plant-based or vegetarian rule from what the product is. When it does, it says so on the result: "Based on product category, not a full ingredient list." It never does this for an allergen rule — a category can't tell you what else was on the production line. And wherever a real ingredient list exists, the ingredient list wins.

The processing score

The 0–100 score is the one thing that's the same for everyone. It reflects how processed a product is, read from how the product is classified and how many additives it declares. Higher means less processed. It doesn't need an ingredient list — a product with a nutrition table still gets a score. It never feeds into your verdict.

What "We can't tell yet" means

"We can't tell yet" is four different situations, not one. Missing ingredient data is the only one photographing the label can fix. An ingredient whose origin isn't stated on the pack (for example E471) is a gap in the label itself — Skop applies the standard you set for that rule (count it as not matching, or as matching with a note) and never guesses the origin. An ingredient we haven't written a rule for yet is our gap, not yours. A "may contain" traces declaration is inherent — check the pack. Everything else Skop knows still shows: the product, its photo, its score and its nutrition.

Skop is not medical or dietary advice

It's a reading aid for labels. For allergies and health decisions, always check the pack itself and talk to a professional.

The words we use

The same terms, meaning the same thing on the label, in the database and in Skop.

Food label

The information printed on a packaged food: the name, the ingredient list, the allergen declaration, the nutrition table and any claims. Its content is set by food-information law in the EU and the UK. Skop reads the label as volunteers transcribed it into the database — and reads it from your photo when the transcription is missing.

Ingredient list

Every ingredient in the product, in descending order of weight. It's the part of the label your rules are checked against.

Ingredient

Skop matches ingredients by a canonical identifier from the open food taxonomy, never by the words on the pack: "E120", "carmine" and "cochineal" are one ingredient. A rule that quietly misses a spelling would be the worst kind of wrong, so free text is never matched.

Additive

An ingredient added for a technical purpose — colouring, preserving, thickening, emulsifying — rather than as a food in itself. The number of declared additives is one of the two things the processing score is read from.

E-number

The code the EU and the UK give a permitted additive: E120 is carmine, E407 is carrageenan, E471 is mono- and diglycerides of fatty acids. A label may print the name, the number or both; Skop treats them as the same ingredient.

Allergen declaration

The part of the label that names the allergens a product contains — in the EU and the UK, the fourteen that must be declared, usually emphasised in the ingredient list — and, separately, a "may contain" line for possible traces. Skop keeps the two apart: a declared trace is never counted as "Matches". Because the data is crowdsourced, always check the pack itself.

Processing score

Skop's own 0–100 measure of how processed a product is, computed from its classification and its declared additives under our own method. Same for everyone, separate from your verdict; it measures processing and nothing else.

Criteria set

The rules you chose — a preset, your own additions, or both. Saved on your phone. A set can be shared as a link if, and only if, you choose to publish it.

Verdict

The result of checking one product against one criteria set: matches your preferences, doesn't match, or we can't tell yet — always with the ingredient and the rule behind it.

Open Food Facts

The volunteer-maintained open database Skop's product data comes from, published under the Open Database License (ODbL). Anyone can correct or complete a product there — including you, from inside Skop.