These two claims sit next to each other on the shelf, look interchangeable, and aren't. If you're tracking sugar for any reason — blood glucose, macros, a dentist's instruction, general preference — the difference matters.
Sugar-free
In the United States this is a regulated claim. To use it, a product has to contain less than 0.5 grams of sugar per serving. That's effectively none.
What it does not tell you is anything about carbohydrates, calories or fat. A sugar-free biscuit is still made of flour. A sugar-free syrup may be nearly carb-free; a sugar-free cake mix is not. The claim is narrow and precise, and it only covers the one thing.
No sugar added
This is a claim about the manufacturing process, not the contents. It means no sugars were added during processing — not that the product contains no sugar.
Fruit and dairy bring their own. No-sugar-added tart cherry concentrate is still concentrated fruit sugar. No-sugar-added cherry pie filling still has cherries in it. No-sugar-added peanut butter is genuinely low in sugar, because peanuts are, but that's peanuts being peanuts rather than the claim doing work.
So: "no sugar added" is a useful signal that nobody sweetened something that didn't need it. It is not a synonym for low-sugar, and it's certainly not a synonym for low-carb.
The sugar alcohol footnote
A lot of sugar-free products get there using sugar alcohols — erythritol, maltitol, xylitol and their relatives. Two things worth knowing.
First, they aren't all equal. Erythritol is largely absorbed and passes through without much metabolic effect. Maltitol behaves considerably more like sugar than its reputation suggests. If a product's carb count seems too good for what it is, check which alcohol is doing the work.
Second, in quantity they cause digestive trouble for a lot of people. The packet often says so in small print. Believe it, and find out where your own threshold is on a day when it doesn't matter.
One more: xylitol is seriously toxic to dogs. If you keep sugar-free gum or mints in a bag a dog can reach, don't.
The four-second check
Turn the pack over and read two lines of the nutrition panel: Total Carbohydrate and Total Sugars, with Added Sugars underneath. Those three numbers tell you more than any claim on the front, and they're standardised so you can compare across brands without translating.
The front of a package is marketing. The back is regulated. Read the back.
Where each one is actually useful
Sugar-free is the right claim to look for in things whose whole purpose is sweetness and which you use in small amounts — syrup, jam, gum, mints, coffee creamer. Those are the products where removing sugar removes most of what you were worried about.
No sugar added is the right claim in whole-food products where sugar was never the point — nut butters, fruit concentrates, tinned fruit, cocoa. There, it tells you the manufacturer didn't take a decent product and sweeten it for the sake of shelf appeal.
Our Sugar-Free & Low-Sugar shelf holds both kinds, and each product page carries the nutrition panel so you can check the actual number rather than trusting the front of the box.