Cronometer vs FOSS: how close can you get without paying?
Cronometer's edge is micronutrient depth. We measure how much of that you can replicate on open source.
Why Cronometer is the relevant commercial benchmark
If you are a serious tracker — bodybuilders dialling in protein, anyone managing iron deficiency, athletes watching electrolytes — the commercial app you actually want is Cronometer, not MyFitnessPal. Cronometer’s edge is that it tracks 80+ micronutrients per food at the database level. MFP tracks ~12. The Cronometer database is also better-curated; the user-submitted entries are flagged separately from the verified ones.
So the question this piece addresses: how close can you get to Cronometer Gold ($59/yr) using only FOSS apps?
Spoiler: about 80% of the way. Read on for what’s missing.
What you actually pay for
Cronometer’s free tier already gives you the database, the search, and basic logging. The Gold tier ($59/yr) adds:
- Custom biometric tracking (blood markers, etc.)
- Recipe import from URLs
- Detailed nutrient targets
- Detailed export
- A handful of QoL features (multiple diary days, copy-paste meals, etc.)
The genuine question for FOSS replacement is: can we get a database with the same micronutrient depth, plus a way to log against it, plus a way to chart trends?
The micronutrient question
Cronometer’s depth comes from layering four data sources: USDA SR Legacy, USDA FNDDS, NCC nutrient lookup, and NutritionTracker.com. Of these, only USDA SR Legacy and FNDDS are genuinely free and bulk-downloadable. NCC is licensed. NutritionTracker is paywalled.
What that means in practice:
| Nutrient class | USDA SR Legacy alone | Cronometer (all sources) |
|---|---|---|
| Macros | Yes | Yes |
| Vitamins (A, B, C, D, E, K) | Yes (most foods) | Yes (more foods) |
| Minerals (Fe, Zn, Ca, Mg, K) | Yes | Yes |
| Choline | Partial | Yes |
| Selenium, iodine | Partial | Yes |
| Lutein, zeaxanthin | Sparse | Yes |
| Amino acids | Yes (less coverage) | Yes (more coverage) |
| Specific fatty acids | Yes for SR Legacy | Yes (more depth) |
The honest summary: USDA SR Legacy plus FNDDS plus Open Food Facts gets you to about 80% of Cronometer’s coverage for the foods most people actually eat. The gap is in obscure micronutrients on obscure foods (selenium content of a specific brand of farmed Atlantic salmon, etc.).
The FOSS stack that gets you there
For someone who wants the full Cronometer-equivalent without paying:
-
Database: pull USDA FoodData Central bulk CSV into Postgres. Add Open Food Facts dump. Total disk: about 6 GiB. We cover this in USDA bulk CSV → Postgres.
-
Tracker app: Waistline on Android (it queries USDA + OFF in a single search) or OpenNutriTracker (OFF only — drops the long tail).
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Charting: Waistline includes nutrient charts but they are surface-level. For anything serious, export to CSV nightly and run Grafana or just a Jupyter notebook.
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Targets: Waistline supports custom nutrient targets at the macro and a half-dozen-micronutrient level. For 80+ targets, you need either a fork or a side script.
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Biometrics: Cronometer integrates body weight, blood pressure, blood markers. The FOSS replacement here is OpenScale (for body) and a CSV in your homelab for the rest. Not as smooth, equally functional.
What you don’t get for free
- NCC nutrient lookup data. This is licensed proprietary. There is no FOSS replacement.
- NutritionTracker.com restaurant data. Same. Restaurants are the consistent FOSS gap.
- Cronometer’s polished UX. The Cronometer iOS app is fast, well-designed, and frankly nicer than any FOSS option.
- A managed sync service. You’ll be running a Nextcloud or similar.
- Detailed lab-marker tracking with reference ranges. You can build this in Grafana but it’ll take an afternoon.
The cost-benefit math
Cronometer Gold: $59/yr. Five years: $295.
FOSS replacement, if you don’t already have a homelab:
- A used Pi 4 / 5 with SD card: $60 once.
- Power: about $10/yr.
- Domain (optional, if you want HTTPS via Tailscale or a reverse proxy): $12/yr.
- Your time, getting it set up: 4–8 hours.
Five years of FOSS: ~$170 plus your time. Five years of Cronometer Gold: $295.
If your time is worth more than $30/hr to you, Cronometer is the rational dollar choice. If you already have a homelab running, FOSS is significantly cheaper and gets you better long-term ownership of the data.
What to do
If you are already running a Pi or a small VPS for other things, build the FOSS stack. The marginal cost is essentially zero and you keep the data.
If you are not yet running a server, and Cronometer’s UX matters to you, pay for Cronometer. It is — among commercial nutrition apps — one of the more conscientious ones. Not perfect (their privacy policy still permits broad telemetry) but among the better-positioned closed-source options for someone who isn’t going to self-host.
References
- USDA FoodData Central: fdc.nal.usda.gov/api-guide
- Open Food Facts: world.openfoodfacts.org/data
- Waistline: github.com/amoses4288/waistline
- OpenScale: github.com/oliexdev/openScale
- USDA bulk CSV → Postgres