They are not the same, though for most household purposes they are close substitutes. Reverse osmosis pushes water through a membrane and leaves contaminants behind in a drain stream. Distillation boils water and condenses the vapor, leaving contaminants behind in the boiler. The results overlap heavily; the practicalities do not.
Two different mechanisms, similar outcomes
A membrane separates by size and charge under pressure, so dissolved salts, metals and most larger organic molecules are rejected while water passes. Distillation separates by boiling point, so anything that does not evaporate with the water stays in the boiler. Where they diverge is at the edges: volatile organic compounds that boil near water can carry over in a distiller unless a carbon stage catches them, while a membrane rejects many of those and relies on carbon for chlorine, which would otherwise damage it.
How they behave in a kitchen
An under-sink reverse osmosis system produces continuously into a storage tank, so water is on tap, it uses no electricity beyond an optional pump, and it sends a share of the feed to drain. A countertop distiller runs in batches of a few hours, uses a meaningful amount of electricity as heat, occupies counter space, and needs the boiler descaled regularly. If you want a glass now, the membrane wins. If you want a jug for a specific purpose, a distiller is simpler to own.
Where the difference actually matters
For drinking, cooking and coffee the two are interchangeable and taste much the same, which is to say flat unless remineralized. For a CPAP machine, a steam iron or topping a car battery, either works and distilled is what the manual usually names. For laboratory or automotive coolant work where specification matters, follow the instruction rather than substituting. For a whole household, only reverse osmosis scales sensibly, since distilling every gallon a family uses is not a realistic proposition.
Choosing between them
Choose reverse osmosis if you want treated water permanently available at a tap, you have space under the sink and the feed pressure to run it. Choose a distiller if you need modest volumes, cannot plumb anything, are renting, or want a device with no membrane to foul. Under-sink reverse osmosis systems are sold in staged configurations with published flow and rejection ratings, and our best reverse osmosis water systems guide compares how those stages are put together.
Questions people ask about is ro water the same as distilled water
Is RO water safe to use where distilled water is specified?
For most household uses such as irons and humidifiers it is fine. Where a manufacturer specifies distilled for warranty reasons, follow the manual.
Which is purer, RO or distilled water?
Distillation usually edges it on dissolved solids, but a staged reverse osmosis system with carbon comes very close and produces water far faster.
Does RO water taste like distilled water?
Both taste flat because dissolved minerals are largely gone. A remineralizing cartridge or a pinch of mineral drops restores body to either.
Can I distill water at home instead of buying an RO system?
Yes, with a countertop distiller, but it works in slow batches and uses electricity, so it suits small volumes rather than whole-household supply.