Sparkling Water vs Soda Water vs Seltzer vs Club Soda vs Tonic Water: What's the Difference?

The Quick Answer

They're all carbonated water, but what's added (or not added) makes each one different. Here's the summary.

Type	What's In It	Calories	Best For
Sparkling water	Water + CO2 (naturally or artificially carbonated)	0	Daily drinking, hydration
Seltzer	Water + CO2 (artificially carbonated)	0	Daily drinking, mixing with fruit
Club soda	Water + CO2 + added minerals (sodium bicarbonate, potassium sulfate)	0	Cocktails, mixing drinks
Soda water	Same as club soda (the terms are interchangeable)	0	Cocktails, mixing drinks
Tonic water	Water + CO2 + quinine + sugar or sweetener	70-90 per can	Gin and tonic, specifically
Mineral water	Spring water with naturally occurring minerals (still or sparkling)	0	Drinking, cooking

Now let's go through each one properly.

Sparkling Water

Sparkling water is the broadest term. It covers any water that has carbonation, whether that happens naturally underground or is added during bottling.

Natural sparkling water comes from a spring or well where the water absorbs CO2 from geological activity. Perrier is the classic example.

Artificially carbonated sparkling water is still water that has CO2 injected into it under pressure. This is what most supermarket sparkling water actually is. The bubbles feel the same and the taste is virtually identical to most people.

There are no additives. No minerals added, no salt, no sugar, no flavouring. Just water and bubbles. Zero calories.

For everyday hydration, sparkling water is the simplest choice. It hydrates you exactly the same as still water. If you're curious about the health side, our guide to carbonated water and health covers the research in detail.

Seltzer Water

Seltzer is artificially carbonated plain water with nothing else added. No minerals, no sodium, no flavouring.

If that sounds exactly like artificially carbonated sparkling water, that's because it basically is. The difference is regional terminology. "Seltzer" is the term used primarily in the United States, named after the German town of Selters, which was known for its naturally carbonated springs.

In Singapore, you'll rarely see anything labelled "seltzer" on the shelf. It'll be called sparkling water. If a recipe from the US calls for seltzer, you can use any plain sparkling water.

The only real distinction: "sparkling water" can refer to naturally carbonated water from a mineral spring, while "seltzer" always means artificially carbonated. In practice, most people use the terms interchangeably.

Soda Water and Club Soda

This is where things get a little different. Soda water and club soda are the same product. Both refer to artificially carbonated water that has minerals added to it.

The typical additions include sodium bicarbonate (gives it a slightly salty taste), sodium citrate, and potassium sulfate. These are added in small amounts, but they're noticeable. Club soda has a slightly salty, mineral quality that plain sparkling water doesn't. It's still zero calories.

Schweppes is the most recognizable club soda brand. In bars and restaurants, when you ask for "soda water," this is what you'll get.

Why add minerals? They mimic the taste of naturally mineral-rich spring water, giving it more body than plain carbonated water. Sodium bicarbonate also buffers the acidity of the CO2, which makes club soda taste smoother and less sharp.

Club soda is the preferred mixer for cocktails. Bartenders choose it over plain sparkling water because those added minerals complement the flavours of spirits.

Tonic Water

Tonic water is the odd one out. It's not really a "water" in the way the others are. It's a sweetened, flavoured carbonated drink.

The defining ingredient is quinine, a bitter compound originally extracted from the bark of the cinchona tree. Quinine was historically used as an anti-malarial medicine. British soldiers in colonial India mixed their medicinal quinine water with gin and sugar to make it palatable, and the gin and tonic was born.

Modern tonic water contains much less quinine than those medicinal doses, but enough to give it that distinctive bitter taste. More importantly, it also contains sugar. A standard 250 ml can has about 20-22 grams of sugar and 70-90 calories. That puts it in the same ballpark as many soft drinks.

"Diet" or "slim" tonic waters use artificial sweeteners instead, bringing the calories to near zero. The taste is different though.

Tonic water is designed for one thing: mixing with gin (or vodka). It's not a health drink and not a substitute for sparkling water. If you're drinking gin and tonics regularly, the tonic is contributing a meaningful amount of sugar to your diet.

Mineral Water

Mineral water comes from a natural underground source and contains dissolved minerals from the rock it passes through. By regulation, these minerals have to be naturally present. They can't be added during processing.

Common minerals include calcium, magnesium, potassium, sodium, and bicarbonate. The exact profile depends on the source.

Mineral water can be still or sparkling:

• Evian - still mineral water from the French Alps
• Perrier - naturally sparkling from southern France
• San Pellegrino - mineral water from Italy with carbonation added
• Gerolsteiner - German, very high in calcium and magnesium

The mineral content actually contributes to your daily intake. A litre of Gerolsteiner provides about 35% of your daily calcium needs. In Singapore, you'll find mineral water at most supermarkets. The label will say "natural mineral water" and list the mineral analysis in milligrams per litre.

Which Is Healthiest?

For daily hydration, plain sparkling water or seltzer is your best bet. Zero calories, zero additives, and it hydrates you just as effectively as still water.

Club soda is fine too, but it does contain sodium. A typical can has around 50-75 mg. That's not a lot, but if you're watching your salt intake and drinking several cans a day, it adds up.

Mineral water is healthy and can contribute useful minerals to your diet, but it's more expensive than making your own sparkling water at home.

Tonic water is the one to watch out for. The sugar content makes it a sweetened beverage, not a health drink. Switching from soft drinks to tonic water doesn't save you much.

If you want the purest sparkling water possible, you can make it yourself at home with a sparkling water maker like the HydroSpark. You start with your own filtered water and add only carbonation. No minerals, no sodium, no mystery ingredients. You control the fizz level and you're not generating plastic bottle waste.

Which Should You Use For...?

Daily drinking and hydration: Sparkling water or seltzer. Plain, no additives, zero calories.

Cocktails and mixed drinks: Club soda for most cocktails (highballs, whiskey soda, mojitos). Tonic water specifically for gin and tonic or vodka tonic. Don't substitute one for the other.

Cooking and baking: Plain sparkling water works well in batter (tempura, pancakes). The CO2 creates air pockets that make batter lighter and crispier. Use sparkling or seltzer, not club soda, as the sodium can affect the taste.

Replacing soft drinks: Sparkling water with a squeeze of fresh lime, lemon, or muddled berries. You get the fizz and flavour without the sugar. One of the most effective ways to kick a soda habit.

Frequently Asked Questions

Is soda water the same as sparkling water?

Not exactly. Soda water (club soda) has minerals added, like sodium bicarbonate and potassium sulfate, which give it a slightly salty taste. Sparkling water is just water and CO2. In casual conversation people use the terms interchangeably, but if a recipe specifies one over the other, it's usually because the mineral content matters for flavour.

Can I use tonic water instead of soda water in cocktails?

You can, but you probably shouldn't unless the recipe calls for it. Tonic water is bitter and sweet. Soda water is neutral. Swapping tonic into a whiskey soda or mojito will completely change the drink.

Is carbonated water bad for your teeth?

Plain carbonated water is mildly acidic due to dissolved CO2, but research shows it's roughly a hundred times less erosive than soft drinks. The American Dental Association considers plain sparkling water "generally fine for your teeth." Tonic water is more of a concern because of the sugar. We cover the dental research in our guide to carbonated water and health.

Why does club soda taste different from sparkling water?

The added minerals. Sodium bicarbonate gives club soda a slightly salty, mineral quality. Potassium sulfate adds body. Some people prefer the cleaner taste of plain sparkling water. Others like the rounded flavour of club soda. It's personal preference.