Hacker News Reader

PSA: decaffeinated coffee contains about 1/3 as much caffeine as regular - so far from caffeine free.

It depends of course but typically it’s more like 3% the caffeine of regular coffee

Decaffeinated is often marked as "97% caffeine free" or something like that, but regular coffee is 91% caffeine free, by weight.

That's not accurate. In an 8oz cup of decaf there's 2–15 mg of caffeine. Regular coffee is about 91 mg for an 8oz cup