LucaCronometer and Luca answer different questions. Cronometer asks what is in your food, down to individual vitamins and minerals. Luca asks roughly how many calories and how much protein, carbs and fat were on the plate, with as little typing as possible.
Where Cronometer is the better choice
- Micronutrients. Cronometer’s website says it tracks up to 95 nutrients and other compounds, with custom macro and micronutrient targets. Luca tracks calories, protein, carbs and fat only.
- Lab-analyzed data. Its support center lists the sources: NCCDB, the US Department of Agriculture, the Canadian Nutrient File and the Irish Food Composition Database, plus label data curated by its own team. Luca’s photo results are estimates.
- Web and more devices. The App Store listing shows iPhone, iPad and Apple Watch, the site links to an Android app, and the support center describes a web version. Luca is iPhone only.
- Free barcode scanning with a verified database. The website says the barcode scanner is free and the database holds over 1M verified foods.
- Depth. Exercise and biometric logging, reports and charts, and in Gold a fasting timer, a recipe importer and Crono Coach.
- Professionals. Cronometer Pro is a separate web platform for dietitians and institutions.
If you track for a specific nutrient, or you want numbers taken from lab analyses and labels, Cronometer is the better fit.
Where Luca is different
- Built around the camera. Photograph a meal and Luca returns an estimate with an item list, and every item and number can be edited. One AI scan a day is free. In Cronometer, photo and voice logging are Gold features.
- Less to fill in. Four ways to log: photo, voice, a typed description or a barcode. If you are new to this, start with macros explained.
- No account. No sign-up and no email. The app uses an anonymous identifier.
- Where the photo goes. Photos are sent for analysis to servers the developer runs, not to a third-party AI provider, and are not stored on the server. Meals live on the device, and in your iCloud if you have it enabled.
- Friends and streaks. Friends, added by a 4-character code, see your streak and badges and whether you logged, never your calories, macros, meals or photos.
- A simpler screen. A daily ring, four targets, recent and favorite meals, and widgets. See macro tracking for beginners.
What neither can promise
A photo is the least certain way to log in either app. Cronometer’s App Store listing says its AI “estimates portions”, and Luca says the same about its own results: they are estimates to review and adjust. If you need tight numbers, weighing food and using label or barcode data gets you closer than a camera, as barcode data vs estimates explains.
Neither app is a medical device, and this page is not medical or dietary advice. Nutrient targets are general information, not a plan made for you.
Checked on 5 October 2026 against the Cronometer pages listed under sources. Prices and features change, so confirm them on Cronometer’s own site. Product names and trademarks belong to their respective owners.
Sources
- Cronometer Gold: plans, prices and features
- Cronometer website
- Cronometer on the App Store
- Cronometer Support: data sources
- Cronometer privacy policy
Last checked on October 5, 2026. Cronometer and other product names are trademarks of their owners. Luca is not affiliated with them. Found a mistake? Tell us and it will be fixed.