20 of the most popular Prime Day 2021 deals our readers bought this year, from Crest Whitestrips to AirPods

Crest 3D Whitestrips

Crest 3D White Professional Effects Whitestrips + Crest 3D White 1-Hour Express Whitestrips Treatment Kit

White strips are arguably the easiest way to brighten your teeth, and you can grab the two-in-one treatment kit on Amazon. Crest 3D Whitestrips are our favorite pick in our guide to teeth whitening kits recommended by dentists, and they hold a top spot in our most-purchased products list every Prime Day.

3D White Professional Effects Whitestrips Kit (button, Preferred: Amazon)
LifeStraw personal water filter, 2-pack

LifeStraw Personal Water Filter for Hiking, Camping, Travel, and Emergency Preparedness, 2-Pack

If you have a camping or hiking trip scheduled, it’s a good idea to pack the LifeStraw Personal Water Filter with you. This less-than-one-pound travel essential will provide 1,000 gallons of clean and safe drinking water.

The LifeStraw removes bacteria and parasites from water as well as microplastics, so you can have the peace of mind of a lightweight, mobile water purifier wherever you go. It’s a no-brainer for hiking, camping, travel, and emergency preparedness. 

This practical and portable accessory jumped up four spots from last year’s list to become the second-bestselling item among Insider readers.

Read our full review of the LifeStraw.

Personal Water Filter (2-Pack) (button)
Fire TV Stick 4K

Amazon Fire TV Stick 4K

Amazon’s Fire TV Stick products are known for their reliable streaming performance, and the Fire TV Stick 4K is the best of the bunch. This tiny stick plugs right into your existing TV’s HDMI port, adding access to popular apps like Prime Video, Netflix, HBO Max, Disney Plus, and more.

As its name implies, the Fire TV Stick 4K can stream in up to 4K resolution with support for all of the major HDR formats. This will ensure you get the very best picture quality, as long as your TV also supports these features. 

Check out all the Amazon Fire TV deals during Prime Day.

Fire TV Stick 4K (button)
Kasa Smart Plug

Kasa Smart Plug

One of our favorite smart plugs, the Kasa Smart Plug is small and affordable. You can fit two into a standard outlet, which isn’t true of all smart plugs. It connects over Wi-Fi, and you control it from a smartphone app. The plug supports Amazon Alexa and Google Assistant, so you can turn devices on and off with voice commands.

Kasa Smart Plug (button)
AirPods Pro

Apple AirPods Pro

Apple AirPods are our favorite wireless earbuds for iPhone users and for good reason. They are convenient to pair and set up, they sound great, and they include noise cancellation technology to help block out distracting ambient noise. These quicly sold out but you can still order them for slightly more than their Prime Day price.

Check out all the best deals on Apple AirPods during Prime Day.

AirPods Pro (button, Preferred: Amazon)
Amazon Echo Dot, 4th Generation

Amazon Echo Dot, 4th Generation

Amazon’s latest Echo Dot ditches the old puck-shaped design of the previous model in favor of a new spherical shape. The tiny smart speaker features Alexa built right in, offering convenient digital assistant support for answering questions, setting alarms, and controlling other smart home products.  

This was the lowest we’ve seen the Echo Dot sell for since it launched in October of last year, so it’s no wonder the Dot was so popular with our readers for Prime Day. 

All-New Echo Dot (4th Generation) (button, Preferred: Amazon)
Belkin BoostCharge

Belkin BoostCharge 15W Fast Wireless Charger Pad

The Belkin BoostCharge is a wireless charging pad for iPhones and Galaxy devices. The pad is a great idea for when you don’t want to fumble for a charging cable in the dark. The Prime Day deal, which was the best we’ve seen on Amazon, was $23.99.

BoostCharge 15W Wireless Charging Pad (button)
Sengled Color Changing Smart Light Bulbs

Sengled Color Changing Smart Light Bulbs

This smart light bulb works with Alexa devices, enabling voice control for turning the light on or off, as well as dimming functions. The bulb is rated for 800 lumens, which is about the same level of brightness you’d get from a traditional 60W bulb. Buyers can also adjust the color of the light to create different moods. 

Smart Light Bulbs (button)
Kindle Paperwhite

Kindle Paperwhite

The Kindle is a beloved e-reader for bookworms and the occasional page flipper alike and now, the brand’s Paperwhite is waterproof and comes with double the storage of the former model. It reads like paper even in bright sunlight and is perfect as a summer beach reading companion.

Kindle Paperwhite (button, Preferred: Amazon)

Waterpik WP-660

The versatile Waterpik WP-660 has 10 pressure settings, so you can adjust based on your gum sensitivity. It holds 22 ounces of water and pulses at the 30-second and one-minute interval so you can keep track of how long you’re flossing for. The Prime Day deal was a big one, with the $70 device marked at $40. 

WP-660 Water Flosser (button)
Stasher Silicone Reusable Storage Bag

Stasher Silicone Reusable Storage Bag

Stasher’s reusable bags are great for those trying to cut down on waste in their kitchens. The silicone bags are safe for the dishwasher and microwave. They’re popular with sous vide users who don’t want to use plastic in heated water. The Prime Day discount offered some great prices on the bags, as well as variety packs with bags in several sizes.

Silicone Reusable Food Storage Bag, 4-pack (button)
Instant Pot Duo Plus 6-Quart

Instant Pot Duo 6 Quart 9-in-1

The 6-quart is a great choice for those who want to cook decent quantities without occupying the whole counter. This was a great deal when it was over half off for Prime Day.

Duo Plus 6-Quart (button, Preferred: Amazon)
Chamberlain MyQ Smart Garage Door Opener

MyQ Chamberlain Smart Garage Door Opener

You consistently upgrade your smartphone, laptop, and clothing, but how about your garage? The MyQ Smart Garage Door Opener enables you to open and close your garage door regardless of location. This is one of the deals that’s still going on, even after Prime Day is over.

myQ Smart Garage Door Opener (G0401) (button)
Beckham Hotel Collection Bed Pillows for Sleeping, Set of 2

Beckham Hotel Collection Bed Pillows for Sleeping, Set of 2

For budget pillows, the Beckham Hotel Collection Gel Pillows are our go-to — inexpensive yet they provide a comfortable, supportive night’s sleep. They’re soft and stackable, sleep relatively cool, machine washable, good for stomach and side sleepers, and hypoallergenic. For a limited time, shoppers can pick up two queen-sized pillows for just $16 each.

Hotel Collection Gel Pillow (Queen) (button, Preferred: Amazon)
Kindle Unlimited Subscription

Kindle Unlimited Subscription

For Prime Day, Amazon offered four months of Kindle Unlimited for free to new members. The subscription service features over one million ebooks, along with unlimited access to audiobooks and up to three magazine subscriptions.

Monthly memberships usually cost $10 and typical trials only last 30 days, so it makes sense that readers jumped at the chance to score four months free of charge.

Kindle Unlimited Subscription (4 Months) (button, Preferred: Amazon)
Fitbit Inspire 2 Health & Fitness Tracker with 1 Year Premium Trial

Fitbit Inspire 2 Health & Fitness Tracker with 1 Year Premium Trial

The Inspire 2 packs all of the standard features buyers expect from a Fitbit into a slim, sleek design that rests comfortably around a user’s wrist. It doesn’t have the most robust features, but it was over 40% off for Prime Day.

Inspire 2 (button, Preferred: Amazon)
5W USB Official OEM Charger

Amazon 5W USB Official OEM Charger and Power Adapter for Fire Tablets and Kindle eReaders

Lots of our readers picked up this wall adapter for Amazon Fire products, like Kindles and Fire tablets. Whether shoppers were looking for a replacement or a spare, we don’t know for sure. Its popularity can likely be attributed to the big Prime Day deals we’ve seen on other Amazon devices that can use the adapter, such as the Kindle Paperwhite and Fire 10 tablet. There was no Prime Day-specific deal, but it’s affordable.

5W USB Official OEM Charger and Power Adapter for eReaders (button, Preferred: Amazon)
Fire Stick, 3rd Generation

Fire Stick, 3rd Generation

The Fire TV Stick is a reliable streaming device that plugs right into your TV’s HDMI port. Once connected, you get access to a huge library of streaming apps. Though this model only supports up to 1080p resolution, that should be just fine for any buyers who are looking to add streaming support to an older HDTV.

Though we recommend the Fire TV Stick 4K over this version, the standard Fire TV Stick does include a newer remote. The updated remote features shortcut buttons for popular apps like Netflix and Disney Plus.

Fire TV Stick (button, Preferred: Amazon)
Eva Dry Wireless Mini Dehumidifier

Eva Dry Wireless Mini Dehumidifier

Got space issues? Whether you live in a tiny apartment, need to dehumidify a closet, or just want something that stores away, the super portable and affordable Eva-Dry Wireless Mini Dehumidifier is handy. Right now you can save 40% on this little device, bringing the price below $15; that’s the lowest we’ve seen for this model

Wireless Mini Dehumidifier (button, Preferred: Amazon)
Amazon Prime Day 2021 FAQs

When is Prime Day?

Amazon Prime Day was on June 21 and June 22.

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What is Amazon Prime Day?

Amazon Prime Day is an online shopping event providing early access to deals for Prime members. If you’d like to take part in all of the deals and discounts, you can register for a 30-day free trial. After that, you’ll be charged $12.99 or $119 per year as a Prime member.

Sign up to be a Prime member here.

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How long will Amazon Prime Day last?

Typically, it’s a two-day sale. Originally, however, it began as a single-day event. This year, it was two days worth of deals on popular items like MacBooks, air fryers, and home goods. A few deals lasted after June 22.

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Do you have to be a Prime member to qualify for sales on Prime Day?

Yes, though you can sign up for the free trial.

To make the most out of your online shopping experience, look out for competitor deals at other retailers, including Target.