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Free U.S. Shipping

Free U.S. shipping on every order. Ships the same business day when ordered by 2pm ET. Arrives in 2–5 business days. Details here.

Fit Guarantee

Fit guaranteed. If it doesn't fit the model we list, we'll send you a prepaid return label within 30 days of delivery. Details here.

Easy 30-Day Returns

Changed your mind? Return it unused, in its original packaging, within 30 days of delivery. Return shipping is free. Cleaners are returnable unopened only.

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Not sure which part fits your appliance? Email support@thinkcrucial.com with your model number and we'll reply within one business day.

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Aftermarket · Made by Think Crucial · Not made by Blueair

Replacement filters for the Blueair Blue Pure 211, 211+ & 221.

Blueair's own store sells the Blue Pure 211+ Particle + Carbon filter for $69.99 each. Ours: $87.99 for 2 ($44.00 a filter), $51.99 less than 2 from Blueair, or $32.75 a filter in the 4-pack. Made by Think Crucial. No subscription.

4.6from 130 ratings on Amazon(as of Oct 1, 2026)

Think Crucial replacement filters for the Blueair Blue Pure 211 / 211+ / 221
Your order · Blue Pure 211 / 211+ / 221In stock
How many filters

Free U.S. shipping · Ships same business day by 2pm ET

Fits, or we pay the return.If it doesn't fit the model we list, email us within 30 days of delivery. We send a prepaid return label and refund you in full. Opened to test the fit is fine.Changed your mind? Return it unused, in its original packaging, within 30 days of delivery. The label is free for these too. Refund policy

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Full product details
The mathblueair.com · Oct 6, 2026
  • Blueair 211+ filter × 2 at $69.99$139.98
  • Think Crucial 2-pack$87.99
You pay less by$51.99

Blueair list price on blueair.com (Blueair's own store) on October 6, 2026, before any sale, coupon or subscription discount.

  • Shipping

    Free U.S. shipping on every order

  • Dispatch

    Ships the same business day when ordered by 2pm ET

  • Fit

    Fit guaranteed on the models listed

  • Returns

    30-day returns with a prepaid label

01How it comparesPrices dated

Think Crucial vs. buying from Blueair.

The same number of filters, side by side. Blueair's price is its list price on blueair.com on October 6, 2026.

Blue Pure 211 / 211+ / 221Think CrucialBlueair, same count
1 filter$51.99$18.00 less$69.99
2 filters$87.99$51.99 less$139.98
4 filters$130.99$148.97 less$279.96
SubscriptionNone. Buy when you need filtersOptional, 15% off ($59.49 a filter)
If it doesn't fitPrepaid return label, full refund, 30 daysBlueair's own terms
Made byThink Crucial (aftermarket)Blueair

Blueair prices: the Blue Pure 211+ Particle + Carbon filter at $69.99 each on blueair.com (Blueair's own store) on October 6, 2026, before any sale, coupon or subscription discount. Blueair also sells the filter on Subscribe & Save at 15% off, $59.49 a filter on a delivery schedule. Every pack above still costs less from us.

02Spec sheetFrom the listing

What's in the box.

Exactly what ships, so you can match it against what's in your purifier now.

In the boxBy pack size
  • 1 ×
    particle + carbon filter
    in the 1-pack, foldable
  • 2 ×
    particle + carbon filters
    in the 2-pack
  • 4 ×
    particle + carbon filters
    in the 4-pack
Fits
Blueair Blue Pure 211, 211+ and 221
Pack sizes
1 for $51.99 · 2 for $87.99 · 4 for $130.99
Subscription
None. Buy when you need filters
Made by
Think Crucial (aftermarket, not affiliated with Blueair)
Ships
Free, from a U.S. warehouse. Same business day when ordered by 2pm ET; arrives in 2–5 business days
03From Amazon4.6 / 5 · 130 ratings

What owners say.

Reviews of this filter on Amazon.com, quoted word for word. Rated 4.6 out of 5 from 130 ratings as of October 1, 2026.

★★★★★
“These filters are a great alternative to Blueair-branded accessories, … I've noticed no difference in quality or filtering ability. Highly recommended.”
Verified purchase · Amazon.com · Dec 4, 2024
★★★★★
“These are very comparable to the brand name filters, at a MUCH better price! They work very well. …”
Verified purchase · Amazon.com · Jan 27, 2023
04CompatibilityBlue Pure 211 / 211+ / 221

Check your model.

Listed for the Blueair Blue Pure 211, 211+ and 221. Two minutes now saves a return later.

  1. 01
    Find the model number

    Check the label on your purifier, your owner's manual or your Blueair order confirmation.

  2. 02
    Match it to this page

    This filter fits the Blue Pure 211, 211+ and 221. It does not fit the 211+ Auto, which takes a different Blueair filter (Blueair part F211PACF106236).

  3. 03
    Still not sure?

    Email your model number to support@thinkcrucial.com and we'll tell you whether it fits. We reply within one business day.

05QuestionsAsked by owners

Before you order.

Straight answers. Anything else, email support@thinkcrucial.com.

Q.01Are these Blueair filters?
No. They're compatible replacement filters made by Think Crucial. They are not made, sold or endorsed by Blueair, and Think Crucial is not affiliated with Blueair.
Q.02Will it fit my purifier?
It's listed for the Blueair Blue Pure 211, 211+ and 221. If it doesn't fit the model we list, email us within 30 days of delivery. We send a prepaid return label and refund you in full, even if you opened it to test the fit.
Q.03What about my Blueair warranty?
Blueair sets its own warranty terms. Check them before switching. Our fit guarantee and 30-day return cover these filters.
Q.04How often should I replace the filter?
Blueair says the red filter light on its 211+ comes on when it's time to change the filter, after about 6 months of operation. That's Blueair's schedule for its own filter.
Q.05Is there a subscription?
No. You buy filters when you need them. Nothing renews and nothing auto-ships.
Q.06When will it arrive?
Free U.S. shipping on every order, from a U.S. warehouse. Ships the same business day when ordered by 2pm ET. Arrives in 2–5 business days.
Q.07Is it the same as Blueair's filter?
No. It's a particle-and-carbon filter made by Think Crucial to fit the Blue Pure 211, 211+ and 221. Blueair markets its own filter technology; we don't make filtration-grade claims for ours. Compare on fit, price and the owner reviews above, and lean on the fit guarantee if it doesn't fit.
Q.08What about the pre-filter?
Blueair sells the 211+ pre-filter as a separate part ($8.99 on blueair.com). Our filters don't include a pre-filter.
Q.09Does it fit the 211+ Auto?
No. The Blue Pure 211+ Auto takes a different Blueair filter (Blueair part F211PACF106236). This filter fits the Blue Pure 211, 211+ and 221.
06Who makes this

We make what we sell.

Think Crucial started in 2007 at a family vacuum repair shop. Today we're a U.S. company in Hollywood, Florida, making aftermarket filters, bags and parts built to fit the machines you already own. Most people can fit the part themselves. They just need the right one, and a way to check it first.

Questions before you order? Email support@thinkcrucial.com. We reply within one business day.

Ready to order

Replacement filters for the Blueair Blue Pure 211 / 211+ / 221

Fits Blue Pure 211 / 211+ / 221
$87.99Free U.S. shipping

Fit guaranteed: prepaid return label if it doesn't fit the model we list. 30-day returns.

Not made by Blueair. These are compatible replacement filters made by Think Crucial, not original equipment manufacturer (OEM) parts. Blueair and Blue Pure are trademarks of Blueair AB, used here only to describe compatibility. Think Crucial is not affiliated with or endorsed by Blueair. Blueair prices from blueair.com on October 6, 2026, before any sale, coupon or subscription discount.

© 2026 Crucial Brands Inc., DBA Think Crucial. Hollywood, Florida.