Comparison · 2 models
Comparing 2 robot vacuums
Your shortlist side by side: today’s price, our score and every fact the maker states.
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- Highest score
- Best on the most facts
Prices updated at 08:46
Side by side
Green is the best of these 2, also when they share the lead.
Drag a model by its header to move its column, or use the arrows.
| | | |
|---|---|---|
| Price and ranking | ||
| Lowest price | – | 132 €OTTO |
| Score | not in our ranking | |
| Rank | – | rank 1 of 1 for small rooms |
| Customer rating | – | – |
| Room size | ||
| Room size | open-plan spacesup to 120 m² | small roomsup to 30 m² |
| Size, noise and age | ||
| How tall the purifier is. It decides whether it fits on a shelf or under a window sill. In this comparisonWhen it matters
| 51.8 cm | 27.4 cm best |
| On the market since | November 2024 | August 2023 |
| Smart features and warranty | ||
| App control same on both | Wi-Fi | Wi-Fi |
| Which voice assistants the robot works with, such as Google Assistant or Alexa. Voice assistants | Alexa, Google Assistant | – |
| Matter is the standard that lets devices from different makers work together. With it you can run the robot outside the maker’s own app. Matter | no (assumed) | – |
| Cleaning performance | ||
| How much clean air the purifier delivers an hour, measured with smoke, dust and pollen. A higher figure cleans a bigger room or the same room faster. In this comparison | 500 m³/h | 140 m³/h |
| The test the CADR comes from. AHAM AC-1 and the DOE test are independent and comparable. A maker's own test is not. CADR measured to same on both | Not stated | Not stated |
| The room size where the purifier changes the air 4.8 times an hour under a 2.5 m ceiling, worked out from its CADR. We use it so every model is compared on the same rule. In this comparison | 42 m² | 12 m² |
| The room size the maker states. Makers use different rules, so we show it but never rank on it. In this comparison | 120 m² | 30 m² |
| Filter | ||
| Whether the particle and carbon layers are one filter or separate ones. Separate filters let you replace only the part that is spent. Filter layout same on both | One combined filter | One combined filter |
| A filter of activated carbon that takes out smells and some gases. It does not catch particles. Activated carbon filter same on both | yes | yes |
| Replacement filter part number | Filter GR; 1712-0118-04 | – |
| How fine the filter is. True HEPA and H13 catch at least 99.97% of particles at 0.3 microns. HEPA-type is a weaker claim with no test behind it. HEPA filter class | – | H13 HEPA |
| Running costs | ||
| How long the maker says a filter lasts, in months of normal use. A filter that is spent cleans less. In this comparison | 12 months | 4 months |
| Noise and power | ||
| The sound level at the lowest speed, as the maker measures it. In this comparison | 23 dB | 10 dB |
| The sound level at the highest speed, as the maker measures it. In this comparison | 56 dB | 50 dB |
| The power the purifier draws at its highest speed. In this comparison | 45 W | 22 W |
| Air quality sensing | ||
| What the purifier measures in the air. A particle sensor lets it speed up and slow down by itself. Air quality sensors same on both | PM2.5 | PM2.5 |
| The fan speed follows the air quality the sensor reads. Automatic mode same on both | yes | yes |
| Build | ||
| Shape | Floor box | Tabletop |
| Width | 286 mm | 206 mm |
| Depth | 286 mm | 206 mm |
| What the purifier weighs. It counts most if you move it from room to room. In this comparison | 4.7 kg | 1.9 kg |
| Extras | ||
| An ioniser charges particles so they settle. Some also make a little ozone, which is why a switch to turn it off matters. Ioniser same on both | Can be switched off | Can be switched off |
| Warranty and certification | ||
| The warranty the maker gives in Germany. Consumer law here stands apart from it and can last longer. In this comparison | 2 years | 2 years |
| Maker model numbers | AT8U457-NWE | CA-503B Compact Smart; CA-503T Compact Smart |
Facts as the maker states them. A dash means the maker does not name it. Each model’s page gives the source of every fact. Noise is the maker’s own figure, so we do not judge it, and a customer rating only counts from 20 reviews.
The score is out of 10: 60% measured facts and 40% shop ratings. A model is ranked only when its CADR is known. Method.
No model fits all these filters.
Lowest price at every shop that delivers to Germany, VAT and delivery included. * = delivery cost and VAT estimated for a foreign shop.
Robot vacuum market report, September 2026 A median price of – and 0 new models.
Frequently asked questions
How big an air purifier do I need?
Match it to the size of the room. Each model in the ranking is grouped by the room size its maker states, and the lists keep a model out when it states none. A common rule of thumb is a clean air delivery rate (CADR) in m³/h of at least 12 times the room’s floor area in m², for a ceiling of 2.4 metres.
What is the difference between HEPA H13 and True HEPA?
Both are high-efficiency filters. True HEPA is the American name for a filter that catches 99.97% of particles of 0.3 micrometres, and H13 is the European class for 99.95%. We read the class the maker states and do not treat a filter called HEPA-type or HEPA-like as either.
Can an air purifier make ozone?
Some can, mostly models with an ioniser or a plasma feature. California limits ozone from indoor air cleaners to 50 parts per billion, and the CARB certification shows a model meets that limit. Our asthma filter leaves out models whose ioniser cannot be switched off.
Where we check prices
We read prices every day at most shops, from their product feed or web shop. We check them for errors and keep them, so you can see what a price did over the last 90 days. We link to Amazon too, but show no Amazon price until we read it through Amazon’s own API. Until then the price is on Amazon itself.
Whose tests we use
Beside each model we also show where these testers place it in their own lists, without counting it in the score:
How we combine measured facts and owners’ ratings into one score is on the method page.
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