Winix Zero Filter A for Air Purifier
A capable multi-stage air purifier with solid filtration, held back mainly by the lack of smart-home features.
The Best Air Purifiers Under £100 in the UK (2026)
You don't need to spend a fortune to clean the air in a bedroom or small room. Here's what you can realistically get under £100 and how to choose well on a budget.
Quick answer
Under £100 you can get a genuinely effective True HEPA purifier for a small-to-medium room or bedroom. Prioritise a real HEPA filter and the right size for the room; accept that you'll compromise on CADR, coverage, smart features and sometimes filter cost.
What you get under £100
Budget purifiers cover small rooms and bedrooms well. You'll typically get a True HEPA filter (often with a basic carbon layer), a few fan speeds and sometimes a sleep mode. What you usually won't get is the high CADR needed for large living rooms, advanced air-quality sensors, or app control - none of which are essential for a small space.
What to prioritise on a budget
- True HEPA (H13 if possible) - never compromise on the filter itself.
- Right size for the room - a budget unit in a small room beats a mid-range one that's still too small.
- Ozone-free operation.
- Affordable, available replacement filters - cheap units sometimes have pricey or hard-to-find filters, which erodes the saving.
The compromises at this price
Expect lower CADR and smaller coverage, simpler controls, and sometimes louder operation at higher speeds. Few budget models have proper sensor-driven auto modes. None of this stops a well-chosen budget purifier doing an excellent job in a bedroom or small office - just don't ask it to clean a large open-plan space.
Common mistakes to avoid
- Buying a cheap ioniser that emits ozone instead of a true HEPA purifier.
- Choosing a unit with expensive or obscure replacement filters.
- Expecting budget coverage figures to clean a large room.
Our top picks
#1
#2 
Xiaomi Mi Air Purifier HEPA Filter Suitable for
A capable multi-stage air purifier with solid filtration, capturing 99.97% down to 0.3 microns, held back mainly by a few practical limitations.
#3 
Bosch Air 500 Purifier
A capable multi-stage air purifier with a CADR of 100 m³/h, held back mainly by the lack of smart-home features.
#4 
Levoit Core 200S Smart HEPA Air Purifier for Allergies & Pets
A capable multi-stage air purifier with solid filtration, capturing 99.97% down to 0.3 microns, held back mainly by a few practical limitations.
#5 
Dyson 360° Glass HEPA + Carbon Filter Pure Cool DP04 HP04
A capable multi-stage air purifier with solid filtration, held back mainly by a few practical limitations.
#6 
SereneLife Air Purifier for Home
A capable multi-stage air purifier with a CADR of 200 m³/h, held back mainly by a few practical limitations.
#7 
Levoit Air Purifier for Bedroom Home
A capable multi-stage air purifier with solid filtration, held back mainly by the lack of smart-home features.
#8 
Evalit Air Purifiers for Bedroom Large Room Up to 2200 Ft²
A capable multi-stage air purifier with solid filtration, held back mainly by a few practical limitations.
#9 
GoveeLife Mini Air Purifier for Bedroom
A capable multi-stage air purifier with solid filtration, held back mainly by a few practical limitations.
#10 
Xiaomi Smart Air Purifier 4 Lite Filter
A capable multi-stage air purifier with solid filtration, capturing 99.97% down to 0.3, held back mainly by a few practical limitations.
Frequently asked questions
Are cheap air purifiers any good?
A well-chosen budget purifier with a True HEPA filter works very well in a bedroom or small room. The savings come from lower CADR, simpler features and smaller coverage - fine for small spaces, not for large rooms.
What should I look for in a budget air purifier?
A genuine True HEPA filter, the right size for your room, ozone-free operation, and affordable, easy-to-find replacement filters so the running cost stays low.
Can an air purifier under £100 cover a large room?
Usually not - budget units are sized for small-to-medium rooms. For a large or open-plan space you'll need a higher-CADR model or two units.
Bottom line
Our top pick is the Winix Zero Filter A for Air Purifier (our score 9.4/10) - A capable multi-stage air purifier with solid filtration, held back mainly by the lack of smart-home features..