Methodology & data sources

Where the data comes from

• Restaurant inspections:each city’s official open-data portal — NYC DOHMH, the City of Chicago, and DataSF. Every restaurant page cites its city’s source dataset and links to it.
• Food recalls: the openFDA Food Enforcement dataset and USDA FSIS recall data, merged into one feed. Every recall links back to the official FDA or FSIS notice.

How we normalize it

Cities grade restaurants in incompatible ways — NYC uses letter grades where lower points are better, Chicago reports Pass/Fail, and San Francisco uses a 0–100 score where higher is better. Radius maps each into one consistent model so results are comparable, while always displaying the city’s original, official grade or score. We never invent a grade; a pending result stays pending.

For recalls, we read the official notice text to categorize the reason and tag major allergens. The agency’s Class I/II/III label is always shown separately from our plain-English explanation of what that class means.

What this data can’t tell you

• An inspection is a snapshot of one day, not a guarantee about your meal.
• Open data can contain errors, duplicates, or delays.
• The absence of a recall or violation does not mean something is safe.

Corrections

If you believe a record is wrong, the authoritative fix is with the agency that publishes it — we link to the official source on every data page so you can verify and report issues at the source.