Toner is the step most people either skip entirely or use without knowing why. That's fair enough, because the word covers two products that do close to opposite things, and the bottle rarely tells you which one you've bought.
Where the confusion comes from
For most of the twentieth century, a toner was an astringent. Cleansers back then were soap-based and alkaline, which left skin at a pH it doesn't like, and the toner was there to strip off what was left and snap the surface back down. It was usually mostly alcohol. It stung, and the sting was sold as the point.
Modern cleansers are pH-balanced, so that job largely stopped existing. The word stayed. It now gets used for two entirely different things.
The two kinds
A toner that removes. Usually built around an acid — salicylic, glycolic, lactic. Its job is to clear what your cleanser didn't reach, which for a salicylic acid means inside the pore, because salicylic is oil-soluble and can get where water-based ingredients can't. This is the one that helps congestion, blackheads and blemishes. It is not hydrating, and it isn't trying to be.
A toner that adds. Built around humectants — usually glycerin, hyaluronic acid, a floral water. Its job is to put a layer of water on your face and hold it there so the serum and moisturiser after it have something to work with. This is the one for skin that feels tight after washing.
Both are called toner. Only one of them will do what you're hoping for, and using the wrong one for months is the usual reason people conclude toner is pointless.
Which one you need
Ask what your skin does two minutes after you wash it.
Tight, dry, a bit papery? You want a hydrating toner. Hydrating Toner is rose water and hyaluronic acid, fragrance-free, and it goes on damp skin — press it in with your hands rather than wiping it off with a cotton pad, because the pad takes half of it back off again.
Oily by mid-morning, congested around the nose and chin, blackheads that come back? You want the acid. Purifying Toner is salicylic acid with no alcohol and no fragrance. Start three or four times a week rather than daily. Every night from day one is how people end up with a stripped barrier and worse skin than they started with.
Both, on different days? That's normal, and it's allowed. Skin isn't one fixed type forever.
Two things worth knowing
Alcohol in a toner isn't automatically bad, but it's usually unnecessary. It's a cheap carrier and it gives you a fast clean feeling. What follows is a slower rebound of oil, because skin that's been stripped compensates. We leave it out of the purifying one for that reason.
A tingle is not evidence of anything. It's the most persistent myth in skincare. A well-formulated acid toner at a sensible concentration can be completely undramatic and still be working. If something stings hard enough that you notice it every time, that's information about your barrier, not about the product's strength.
Do you need one at all?
Honestly, no. A cleanser, a moisturiser and an SPF is a complete routine and will get most people most of the way. Toner is the first thing worth adding after that, not the first thing to buy.
What it does, when it's the right one, is make the steps after it work better — a hydrating toner by leaving skin damp for whatever goes on next, an acid one by clearing the way. That's a real effect, and it's a smaller effect than the marketing suggests.
If you're not sure which half of your face you're solving for, the 30-second skin quiz will get you to an answer faster than another hour of reading will.