Litmus Label Reader

iPhone app by Kamal Nasir

Food label reader for iPhone: Litmus reads a package's ingredient list back to you, marks flagged ingredients and your allergens, and works offline.

What it does

• Point at a barcode to look the product up in a bundled database of about 440,000 US products
• If a product is not there, fill the window with the printed ingredient panel and tap Read the printed list, which works on any labelled product, cosmetics included
• Shows the ingredient sentence exactly as printed and in label order, with each flagged word highlighted where it sits and any word it could not place marked with a question mark
• Tick the allergens on your list and every scan is read against them, with matching words set in red
• Notes beneath the label explain each mark, give its evidence tier, and cite a regulation or assessment that opens the source document
• Works with no internet: the product database and ingredient rules are on the phone, nothing is uploaded, no photo is saved, and there is no account
• Where the nutrition data is complete, a 0 to 100 score from the published Nutri-Score algorithm plus additive and organic weighting, shown with its sub-scores; where it is incomplete, no score

Litmus is an information tool, not medical advice. A label cannot rule out cross contact, so always verify with the manufacturer or your clinician.

Questions people ask

Can an app scan food labels for allergens?

Yes. Litmus looks a barcode up in a bundled database of about 440,000 US products, or reads the printed ingredient list with the camera, and checks each scan against the allergens you tick. When nothing matches it reports "no flagged ingredients found" and asks you to verify, because a label cannot rule out cross contact.

Is there a food ingredient scanner that works offline?

Litmus works with no internet connection. The product database and the ingredient rules are stored on the phone, so it reads labels in a basement aisle, on a plane, or abroad with data switched off. Nothing is uploaded and no account is needed.

Does Litmus rate foods as good or bad?

No. Litmus does not call products dangerous. Its marks describe the strength of the evidence on an ingredient, from strong human evidence down to no current evidence of concern at permitted use, and each one cites its source.

Comparing apps? See the guide: Best food ingredient scanner and label reader apps for iPhone in 2026.

More apps by Kamal Nasir

• Kamera Pro: LiDAR Night Vision
• Nocturne: Card Value Scanner
• HydroNest Family Water Tracker
• Halo: Migraine Tracker
• IBS Tracker Food Diary: Fennel
• Halal Scanner - Dalil
• ChartKey: Medical Keyboard
• Therapy Notes Keyboard NoteKey
• BPM, Key and Loudness: Quint
• Drone Weather Hourly: Pitot
• Jolt: Tic Tac Toe

Published by Kamal Nasir, the developer of the apps marked Ours. Apps change, so check each one's App Store page for its latest features.