Reverse Osmosis vs Distilled Water: Differences and Which One to Choose

Both reverse osmosis and distillation are highly effective methods of purifying water. However, although both technologies are designed to reduce impurities and contaminants, they work in very different ways and are not always intended for the same applications.

If you're comparing reverse osmosis water and distilled water for drinking, cooking, using in a humidifier, or simply improving your home's water quality, it's important to understand the differences and which option is best suited to your needs.

In this guide, we explore their main differences, advantages, disadvantages, and the most common applications to help you make an informed decision.

What is the main difference between reverse osmosis and distilled water?

The main difference lies in the purification process.

Reverse osmosis uses a semi-permeable membrane capable of removing a wide range of contaminants, dissolved salts, and particles from water.

Distillation, on the other hand, works by boiling water until it turns into steam and then condensing it back into liquid form. During this process, most impurities are separated from the water.

Both methods are highly effective, but they differ in terms of cost, energy consumption, production speed, and everyday convenience.

What is reverse osmosis water? A simple explanation

Reverse osmosis water is water that has passed through a membrane designed to reduce a broad range of contaminants commonly found in drinking water.

This type of filtration can help reduce:

• Heavy metals such as lead and arsenic
• Nitrates
• Chlorine
• Pesticides
• PFAS
• Microplastics
• Dissolved salts

The US Environmental Protection Agency (EPA) recognises reverse osmosis as one of the most effective technologies for reducing numerous contaminants found in drinking water in its Home Drinking Water Filtration Fact Sheet.

If you'd like to learn more about how the process works, read our guide on what reverse osmosis is and how it works.

What is distilled water and how is it produced?

Distilled water is produced through a process of evaporation and condensation.

First, water is heated until it boils. The steam is then collected and cooled so that it condenses back into liquid water.

During this process, minerals, salts, and a large proportion of impurities are removed, resulting in exceptionally pure water.

For this reason, distilled water is commonly used in:

• Laboratories
• Medical equipment
• Batteries
• Steam irons
• Certain industrial processes

Although distilled water is safe to drink, it is not usually the preferred choice for everyday household consumption.

Reverse osmosis vs distilled water: At a glance

Feature	Reverse Osmosis	Distilled Water
Purification method	Semi-permeable membrane	Evaporation and condensation
Contaminant removal	Very high	Very high
Mineral removal	Yes	Yes
Energy consumption	Low	High
Water production	Continuous	Slower
Everyday household use	Very common	Less common
Long-term cost	More economical	Higher
Technical applications	Limited	Very common

Which is better for drinking every day?

For most households, reverse osmosis is generally the more practical choice for everyday drinking.

Why?

Because it provides a continuous supply of filtered water directly at home, without the need to boil water or use large amounts of energy.

In addition, many modern systems include remineralisation stages to improve taste and provide a more balanced mineral profile.

The World Health Organization (WHO) notes in Nutrients in Drinking Water that drinking water can contribute to the intake of certain minerals, although food remains the primary source of essential nutrients.

For this reason, many people choose reverse osmosis systems with remineralisation for daily drinking water.

If you'd like to explore the topic further, read our article on drinking reverse osmosis water every day.

Which is better for cooking?

In most situations, reverse osmosis water is the more practical option for cooking.

Its lower concentration of chlorine and other compounds can help preserve the natural flavour of:

• Soups
• Rice
• Pasta
• Coffee
• Tea
• Herbal infusions

Because it's readily available from a home filtration system, it's also much more convenient for everyday cooking.

You may also find our guide on cooking with reverse osmosis water useful.

Which water is better for humidifiers?

Both distilled water and reverse osmosis water can be suitable choices for many humidifiers.

They can both help reduce:

• Limescale deposits
• Mineral build-up
• White dust commonly produced by ultrasonic humidifiers

However, for everyday household use, many people choose reverse osmosis water because it's more convenient if they already have a filtration system installed at home.

Learn more in our article on reverse osmosis water for humidifiers.

Which water is better for coffee machines, kettles and household appliances?

Limescale build-up is one of the main issues affecting coffee machines, kettles, and many other household appliances.

Both distilled water and reverse osmosis water can help reduce scale formation.

However, for everyday use, reverse osmosis is generally the more practical option because it provides a continuous supply of filtered water without the need to buy or produce distilled water on a regular basis.

Which water is best for laboratories, steam irons or batteries?

In these situations, distilled water is generally the preferred option.

Many technical applications require water with an extremely low mineral content to avoid deposits or interference.

For this reason, distilled water remains the standard choice for:

• Laboratories
• Batteries
• Steam irons
• Certain medical devices

Advantages and disadvantages of reverse osmosis water

Advantages

• Reduces a broad range of contaminants.
• Convenient for everyday drinking.
• Provides filtered water directly at home.
• Can include remineralisation.
• Helps reduce reliance on bottled water.
• Relatively low running costs.

Disadvantages

• Requires regular maintenance.
• Produces wastewater during the filtration process.
• Removes naturally occurring minerals from the water.

Advantages and disadvantages of distilled water

Advantages

• Extremely high level of purity.
• Ideal for technical and scientific applications.
• Removes virtually all minerals and dissolved salts.

Disadvantages

• Slower production process.
• Higher energy consumption.
• Less practical for producing large volumes of water.
• Typically more expensive for everyday use.

So, which option should you choose?

The answer depends mainly on how you intend to use it.

For everyday drinking

Reverse osmosis is generally the most practical and convenient choice.

For cooking

Reverse osmosis typically offers the best everyday experience.

For humidifiers

Both options can work well, although reverse osmosis is often more convenient for households with an existing filtration system.

For technical or laboratory applications

Distilled water remains the preferred solution.

Is a remineralisation system worth it?

In many cases, yes.

Remineralisation systems add minerals such as calcium and magnesium back into the water after filtration to improve taste and create a more balanced mineral profile.

Discover our home reverse osmosis systems featuring advanced filtration and remineralisation technologies.

Conclusion: Reverse osmosis for everyday use, distilled water for specialist applications

Both reverse osmosis and distillation are highly effective methods of water purification.

However, for most people looking to improve the quality of the water they drink and cook with at home, reverse osmosis offers the best balance of performance, convenience, and long-term value.

Distilled water, on the other hand, remains the preferred choice for specialist technical applications where exceptionally high purity and minimal mineral content are essential.

Frequently Asked Questions

Is reverse osmosis water the same as distilled water?

No. Both are purified forms of water, but they use different purification processes and are suited to different applications.

Can you drink distilled water every day?

Yes. However, it is not usually the preferred option for everyday drinking because of the cost and the way it is produced.

Is reverse osmosis water or distilled water better for cooking?

For most households, reverse osmosis water is the more practical and convenient choice.

Which water is better for a humidifier?

Both distilled water and reverse osmosis water can help reduce mineral build-up inside the appliance.

Does reverse osmosis remove minerals?

Yes. That's why many modern reverse osmosis systems include remineralisation stages.