The under-£100 category of air purifiers has improved significantly in recent years. A few years ago, anything below £100 was likely to use a HEPA-type filter with mediocre particle capture. Now there are True HEPA options — models with independently verified 99.97% filtration at 0.3 microns — available for under £80.
The honest limits of this price bracket: you won't get large-room coverage, you won't get premium smart features with a PM2.5 sensor, and you won't get ultra-quiet operation. What you will get is functional, verified HEPA filtration for smaller rooms at a modest annual running cost.
This guide is deliberately different from our budget air purifier guide, which focuses on value broadly. This one is price-banded — specifically what the best option looks like at each price point under £100.
Under £50: The Reality Check
There are air purifiers for sale under £50 on Amazon UK. Most of them are not worth buying.
At this price point you will typically find: HEPA-type filters (not True HEPA), very small room coverage (10-15m²), noisy operation, plastic construction that won't last, and replacement filters that are expensive relative to the unit cost and sometimes impossible to source after a year.
The two partial exceptions are very small desktop units with True HEPA — designed for a desk surface rather than a room — and basic ionisers, which don't use replaceable filters but whose effectiveness is limited to the ionisation mechanism rather than mechanical filtration.
Recommendation: There is no under-£50 pick we'd endorse for general room air purification. Stretch to £75 minimum for a True HEPA unit worth buying.
Under £75: The Sensible Entry Point
Levoit Core 300 — ~£80 (regularly on sale under £75)
The Core 300 lists at around £80 but is regularly discounted to £69-75 on Amazon UK, particularly in the run-up to Prime Day and around Black Friday. At those prices, it's the best air purifier you can buy for under £75 by a significant margin.
True HEPA filter (H11-H13 grade), CADR of 187 m³/h, coverage to 80m², 24dB sleep mode, activated carbon. No smart features. Three fan speeds plus sleep mode. Compact form factor.
This is the one to check the Amazon price on before buying anything else. If it's £75 or under, buy it.
Specs
- CADR: 187 m³/h
- Coverage: 80m²
- Noise: 24dB (sleep mode)
- Filter: True HEPA + activated carbon
Under £100: The Full-Price Picks
1. Levoit Core 300 — Best Under £100 Overall
At its full £80 list price, the Core 300 remains the strongest value pick. The filtration is genuine, the noise is acceptable, and the filter costs are reasonable. If you want the most reliable air purifier for the least money, this is it.
When to choose it: if you just want clean air in a bedroom or home office and don't need smart features.
2. Coway Airmega 100 — Best for Quiet Use Under £100
The Coway Airmega 100 is the pick if you specifically need quiet operation. Its 18.4dB sleep mode is quieter than the Levoit's 24dB, and its CADR of 244 m³/h is notably higher than the Core 300's 187 m³/h. The air quality indicator gives a real-time read on particle levels.
At around £80-100, it competes directly with the Core 300 and has advantages in noise and raw CADR. The Core 300 wins on compact form factor and simplicity.
When to choose it: light sleepers who want quiet operation and better CADR per pound.
3. Levoit Core 200S — Best Smart Pick Under £100
The Core 200S is the only smart purifier (Wi-Fi, Alexa, app scheduling) reliably available under £100. Coverage is 64m², which is smaller than the Core 300. It doesn't have a PM2.5 sensor for auto mode — you schedule it or control it manually via the app.
At roughly £99, it's right at the limit of this category. But if smart home integration is important to you and you'd otherwise be frustrated by a manual-only purifier, it's worth the extra £20 over the Core 300.
When to choose it: smart home users, Alexa/Google households, people who want scheduling.
What to Watch Out For Under £100
HEPA-type claims. The under-£100 market is full of purifiers claiming HEPA performance without True HEPA specification. Always check that the product page explicitly states "True HEPA" or quotes an H-grade (H11-H14).
Filter availability. Some cheap purifiers use proprietary filters that are hard to source after the unit is more than a year old. Before buying any purifier, search for its specific replacement filter on Amazon UK and check availability and price. If there's only one listing and it's from a brand you've never heard of, that's a risk.
Room size inflation. Budget purifiers often quote room coverage in m² without specifying the ACH rate assumed. "Covers 50m²" might mean 1 ACH — barely adequate for general use. The Levoit Core 300's 80m² figure assumes 2 ACH, which is more useful.
See our budget air purifier guide for a broader value-oriented view, or our full air purifier roundup for the complete picture across all price points.