Potatoes. Oil. Salt. That's how it should read. For a surprising number of chains it doesn't — there's beef flavor, wheat derivatives, milk solids, shared fryers, and quiet chemistry most menus never mention. This is the field guide we couldn't find, so we're writing it.
We thought "fried potato" was a solved problem. It wasn't. Here's the quick tour.
McDonald's U.S. fries are flavored with a beef-derived ingredient that contains hydrolyzed wheat and hydrolyzed milk. Not vegetarian. Not vegan. Not gluten-free. Not dairy-free. In Canada and much of Europe, the same item is made differently.
See the full breakdownMost chains cook fries in the same oil as breaded chicken, fish, or onion rings. Even when the potato itself is technically gluten-free, a shared fryer can make it unsafe for someone with celiac disease. Almost no menu advertises this clearly.
Find dedicated-fryer chainsPeanut, canola, vegetable blend, beef tallow — each one changes who can eat the fries. Five Guys uses 100% refined peanut oil. In-N-Out and Chick-fil-A use their own distinct blends. Most "vegetable oil" is soybean oil. The difference isn't trivial.
How we evaluate oilsTap a box. We'll show you only the fries that clear your bar.
Twenty-seven chains audited so far — down to the ingredient and the fryer. The original Frypedia atlas is complete; we're already adding more chains. Each entry is sourced from the chain's own allergen disclosures.
On a drive up from the Virginia coast to Baltimore — the kind where you're peckish and the exits all have the same dozen signs — we started pulling up allergen pages on our phones. My wife has been vegetarian most of her life. I've been vegetarian about six years, and don't do dairy either. We both eat fish, but no meat.
We'd had those fries before. Probably dozens of times. We had not read the ingredient list. When we did, one chain's U.S. fries turned out to contain a beef-derived flavoring, milk derivatives, and wheat derivatives. Another, a few exits up, listed three ingredients: potatoes, peanut oil, salt. The contrast was almost funny, except we'd spent years eating one of them thinking it was fine.
This site is the resource we wanted that afternoon. Every chain, every fry, every ingredient — audited against the chain's own disclosures, updated as they change, with a clear verdict per diet. No affiliate links. No recipes. Just the fries.
Read the full storyBeyond the chain-by-chain verdicts, we're building a reference on the fry itself — where the Americans call them "french" and the British call them "chips," how ~4.5 billion pounds of frozen fries move through U.S. foodservice every year, and why the same chain's recipe changes across borders.
Belgian origins, American arrival, and the moment McDonald's invented the modern fast-food fry.
Canola vs. peanut vs. beef tallow vs. soybean — what each oil means for flavor, nutrition, and who can eat it.
Cross-contamination, why it matters, and which chains run dedicated fryers for their potatoes.