A purifier that costs $100 or less still has to run all night a few feet from a bed, or all day beside a desk. At this price the questions are a little different from the ones in our main guide to the quietest air purifiers. The machines are small, so room size matters more. Few of them have sensors or apps. And the filter, bought again and again, often costs more than the purifier over a few years.
We looked for HEPA purifiers with a maker list price of $100 or less, on the maker's own US store, and kept only the ones whose maker publishes a noise figure we could quote. This guide covers noise, size and running cost. We make no health claims, and we have left the makers' health claims out.
Our picks are listed above, with full specifications for each.
How we set the $100 limit
We used each maker's list price on its own site, checked on October 4, 2026, and nothing else. Sale prices move, so they do not decide eligibility here. When a sale takes a unit under $100 we say so plainly:
- Levoit Core 300-P: $99.99 list, on sale at $84.97. It qualifies on list price.
- Levoit Core Mini-P: $49.99 list, on sale at $43.99.
- Medify MA-14: $88.99 on Medify's store; the black version shows $99.99 struck through. It qualifies either way.
- Winix A230: $129.99 list, on sale at $99.99 and out of stock. It does not qualify.
- Blueair Blue Signature Small, Knicks Limited Edition: $99.99 against $199.99. It does not qualify.
Some names buyers expect are not here. Coway lists the Airmega 100 at $129.99, so no current Coway purifier is under $100 on its own store; our Coway Airmega decibels page lists them all. On Winix's store, the cheapest purifier we found was the A230 at $129.99 list; our Winix air purifier decibels page covers the rest. Shark's HP102 is $199.99. The Blueair Blue Pure 411 is no longer on Blueair's US store; the current 411i+ Max costs more than $100.
Other makers sell purifiers at or under $100 but print no noise figure in the page text we read: Dreo for the 338, 338S, 539 and Macro AP314, and Vornado for the QUBE50, CYLO50 and Purio Nursery. We could not read Bissell's US site, which refused our requests, and we found no Honeywell noise figure. We do not rank any of them.
Makers quote different settings in different units. A figure in dB is not the same thing as one in dBA, and a figure for Sleep Mode is not the same as one for speed 1. So we compare only figures with the same unit and the same setting label, and we treat no gap of a decibel or two as real, because no maker states a distance. Our page on why you cannot compare dB ratings across brands explains why.
Labelled low and high, in plain dB. Only the Blueair Blue Pure Mini Max Auto: "Low: 19 dB High: 44 dB". Blueair's FAQ repeats both. No other qualifying unit labels both ends in dB without contradicting itself, so there is nothing to rank it against.
Labelled low and high, in dBA. The Medify MA-14 and the GermGuardian AC4825 can be set side by side. Medify's manual says "Speed 1 is low" and gives it 29.5 dBA; GermGuardian lists "Noise dB-Low 40 dBa". At the top, Medify's speed 3, which the manual calls "fast", is 48.3 dBA, against GermGuardian's 55 dBa on high. On both counts the Medify is the quieter of the two, by 10.5 dBA on low. On the rough rule that 10 dB sounds about twice as loud, that is a large gap.
Sleep Mode. Levoit ties a figure to it for the Core 200S-P: "as low as 27dB". Medify lists 26 dBA in Sleep Mode for the MA-14. One is dB and one is dBA, so we do not say which is quieter.
Ranges with neither end labelled. The Levoit Core 300-P prints 24-54.5dB and the Core Mini-P 25-44dB. Levoit does not say which setting either end describes, so we rank neither on its low figure. Our Levoit air purifier decibels page groups every Levoit model by what its figure describes.
Two figures on one page. The Blueair Blue Pure 511, at $99.99, says "24-49 dB" in its spec table and 22 dB low and 44 dB high in its FAQ. We list it but give it no award. Our Blueair air purifier decibels page lists the other Blueair pages that disagree with themselves.
The room it really covers at a quiet speed
This is the part a $100 purifier gets wrong most often. The room sizes on these pages are at full speed. Medify says so in its footnote: the smoke CADR is "when operating at highest fan speed". The EPA says the same about CADR in general, and AHAM's rule of thumb is a smoke CADR of at least two-thirds of the room's area.
Here is what each maker rates its unit for at 4.8 air changes an hour, AHAM's basis:
- Levoit Core Mini-P: 53 sq ft
- Medify MA-14: 89 sq ft on the product page, 117 in the manual
- Blueair Blue Pure Mini Max Auto: 105 sq ft
- Levoit Core 200S-P: 140 sq ft
- GermGuardian AC4825: 153 sq ft ("Cleans a 153 sq. ft. room in just 12.5 minutes")
- Blueair Blue Pure 511: 189 sq ft
- Levoit Core 300-P: 222 sq ft
None of these makers publishes how much air its unit moves on its lowest speed. The makers that do, at higher prices, show how big the drop is: Alen lists 66 CFM at speed 1 against 190 on Turbo for its BreatheSmart 35i, about a third, and IKEA lists 29.4 CFM at the lowest speed against 141 at the highest for the STARKVIND, about a fifth. We cannot say whether these budget units fall by the same amount, but we would not expect them to keep their rated room on their quietest setting.
So our rule of thumb, which is ours and not a maker's: if you want a budget purifier to run on its quiet setting, put it in a room of no more than about half its rated size at 4.8 air changes an hour. That makes the Core 300-P the only pick here with clear headroom in an ordinary 10 by 12 foot bedroom of 120 sq ft. The Core 200S-P and Mini Max Auto suit a nursery or box room. The Core Mini-P suits a desk.
The filter is the real price
Every unit here costs less than $100. The filters do not stop. Using each maker's own price and replacement interval:
- Levoit Core 200S-P: $25.99, replaced every 6 to 8 months per the manual. About $39 to $52 a year.
- Blueair Blue Pure Mini Max Auto: $21.99 for the Particle + Carbon filter. The product page says every 6 months, about $44 a year; the manual says 6 to 9 months.
- Levoit Core 300-P: $29.99. The manual says the check filter light should come on within 6 to 8 months. About $45 to $60 a year.
- Blueair Blue Pure 511: $23.99, every 6 months. About $48 a year.
- GermGuardian AC4825: $24.99 for the standard Filter B. GermGuardian's filter pages recommend a new HEPA filter every 6 months, about $50 a year, plus carbon filters every 2 to 3 months.
- Levoit Core Mini-P: $24.99 list, every 4 to 6 months. About $50 to $75 a year.
- Medify MA-14: $39.99 for a filter rated for 2,500 hours, which Medify puts at 3 to 4 months. About $120 to $160 a year at that rate.
The Medify figure needs a note. Its 3 to 4 months assumes the unit runs nearly all the time. By our arithmetic, 2,500 hours at 8 hours a night lasts about 10 months, which brings the bill down to roughly $48 a year. In a bedroom used only at night, the MA-14 is not as dear as it first looks. In an office running all day as well, it is.
Over three years, most of these units need about $115 to $180 of filters on their makers' figures, more than the purifier. The MA-14 run around the clock would need several times its own price. A filter that is overdue also makes noise of its own: Levoit's Core 200S manual lists "Increased noise when the air purifier is on" as a sign the filter needs replacing.
What you give up at this price
Sensors and auto mode. Only the Mini Max Auto has an air quality sensor. That is not a loss in a bedroom: with no auto mode, a fan cannot ramp up in the night when the sensor sees dust. In a quiet bedroom a fixed low speed is what you want anyway.
Smart features. Only the Core 200S-P has an app, with schedules and a timer of 1 to 24 hours. The rest are button-only.
Labelled figures. Three of our five picks print a figure tied to a named setting. The Levoit Core 300-P and Core Mini-P print bare ranges.
Size and airflow. The biggest unit here is rated for 222 sq ft. For more, the parent guide's advice to size up costs more than $100.
Lights. These vary more than you might expect. The Mini Max Auto's Night Mode goes to its lowest brightness. The Core 200S-P turns its display completely off in Sleep Mode, though its night light has its own button. The Core 300-P's indicators go to half brightness in Sleep Mode, and it has a Display Off button. The MA-14 turns all lights off except a dim S button. The Core Mini-P's lights go off after 60 seconds.
Which one for which room
A bedroom. For a typical 120 to 150 sq ft bedroom, the Levoit Core 300-P has the room to run on a low speed. If you want the night figure in writing, the Core 200S-P lists 27dB in Sleep Mode, but it is rated for 140 sq ft, so in a room that size it may need its louder speeds. For more on setting up a bedroom for sleep, see our bedroom air purifier guide.
A nursery. Nurseries are often small, which suits these units. The Mini Max Auto, rated for 105 sq ft, labels both ends of its range and dims fully in Night Mode. Our nursery air purifier guide covers child locks, cords and lights, and our page on a quiet nursery covers the room as a whole.
A small office. In an office, the purifier runs all day, often on a middle speed. Only Medify publishes a middle-speed figure here: 37.2 dBA on speed 2 for the MA-14. On a desk, the Core Mini-P is sized for the space around you, not the whole room. Our home office air purifier guide looks at the speed you run through a workday, and our page on a quiet home office covers the other machines in the room.
How we chose
We listed the HEPA purifiers on each maker's US store with a list price of $100 or less, checked on October 4, 2026. For each one we read the product page and, where one is published, the manual, and recorded the noise figure in the maker's words with the setting it describes. We recorded room sizes at 4.8 air changes an hour, CADR as the maker states it, and the filter's price and replacement interval from the maker's own store. We ranked for a bedroom, nursery or small office: a figure tied to a named setting, enough rated room to run quietly, and a filter bill you can live with.
We did not measure any of these purifiers ourselves. Every figure here comes from the maker's own page or manual, no maker states the distance or standard behind its noise figure, and the yearly filter costs are our arithmetic from the makers' own prices and intervals.
