How do you know whether a product contains gluten by scanning it?

A scanner reads the barcode, finds the ingredient list in a database (most often Open Food Facts) and analyses it. For a coeliac, it must recognise wheat, barley and rye under all their names, flag derivatives whose origin is not specified, and above all read "may contain traces" statements. A scanner that ignores traces is not a scanner for coeliacs.

Is a gluten-free scanner 100% reliable?

No, and it should not claim to be. The database may be incomplete or out of date, and a manufacturer can change a recipe without the database following. A good scanner says what it knows and what it does not, and sends you back to the label. Nutrixe never says "gluten-free": it says what the list contains and what remains uncertain.

Is the Nutrixe scanner free?

Yes, with no limit on scans, no account and no ads. The subscription adds offline mode, travel lists and the notebook, not the scanner.

Which barcode scanner for gluten? What a coeliac should demand

Every scanner reads the same label. What sets them apart is what they do with "traces" statements, wheat derivatives and oats. The criteria that matter, and five apps measured against them.

Every scanner does the same thing at first: read a barcode and find the ingredient list. The difference, the one that matters to a coeliac, lies in what they do next with that list. Here are the criteria, then five apps measured against them.

The five criteria of a scanner for coeliacs

1. It reads “traces” statements. “May contain traces of wheat” appears at the end of the list, outside the ingredients. A product with no wheat in its recipe but made on a line that handles it is a real risk. A scanner that only analyses the ingredient list and ignores that statement will tell you “nothing to report” about a dangerous product.

2. It knows gluten’s names. Wheat is also called spelt, einkorn, kamut, bulgur, couscous, semolina, seitan; barley hides in malt, malt extract, brewer’s yeast; rye is quieter but exists. A scanner that looks for the word “gluten” will find nothing in “barley malt extract”.

3. It flags what is uncertain. “Starch” with no origin, “glucose syrup” with no origin, “flavourings”: that is not gluten, nor is it a guarantee. A good scanner says so instead of deciding.

4. It does not say “gluten-free”. A database is never today’s recipe. The manufacturer may have changed the formula yesterday. The scanner that displays “gluten-free ✅” promises what it cannot know; the one that displays “no gluten ingredient in the declared list — check the label” tells you the truth.

5. It admits what it does not know. A product absent from the database must return “unknown”, not a default score, and offer to send the label so the next person is served.

Five apps against these criteria

Nutrixe

Built around these five criteria, because that is the reason it exists. It reads the list the way a coeliac would — wheat, barley, rye and derivatives, starch of unspecified origin, oats outside a certified chain, traces — and gives a nuanced verdict: what the list contains, what it leaves uncertain, and always check the label. Unknown product: it says so and offers to send the label. Free without limit, no account, no ads, in six languages. It also carries a map of 3,274 verified places.

Limit: it does not rate nutritional quality. That is not its question.

Yuka

The most installed scanner, and the most misunderstood by coeliacs. Yuka rates nutritional quality out of 100. The gluten alert is part of the food preferences, reserved for Premium, and does not take “traces” statements into account — it is written in its help centre. Criteria 1 and 4 not met. Keep it for nutrition. The details.

Fig

The most complete restriction scanner in the United States. You declare a profile (Fig tells coeliac disease, wheat allergy and sensitivity apart), you scan, the result is colour-coded with the ingredients concerned. It handles several restrictions at once. Subscription after the trial, mostly US database, English. If you live in the United States, it is an excellent choice.

Spoonful

Same principle as Fig, simpler: profile, scan, verdict. Fewer features, same American audience.

Open Food Facts (the app)

The database itself, with its official app. You will see the raw ingredient list and declared allergens, without coeliac interpretation: it is up to you to read. Free, open, and the source for most of the others — Nutrixe and Yuka included. Useful for contributing: every label photographed serves everyone.

The table

	Traces read	Gluten’s names	Uncertain flagged	Says “gluten-free”?	Free
Nutrixe	yes	yes	yes	never	yes, unlimited
Yuka	no	partly, Premium	no	score out of 100	alert in Premium
Fig	yes	yes	by profile	colour codes	trial then subscription
Spoonful	yes	yes	limited	colour codes	limited
Open Food Facts	shown, not interpreted	up to you	—	no	yes

What no scanner replaces

The label, physically, in your hand. The manufacturer can change the recipe without telling the database. The scanner saves you time and spares you the vocabulary traps; the label has the last word. A scanner that tells you otherwise is lying to you.

State as of 5 September 2026. Something inaccurate? Tell us.