More sustainable than new

Galaxy S21 Ultra 5G 128GB - Dark Gray - Unlocked

1 / 3.
Buy now, pay later.

Free delivery
Works with all carriers

Comes with

Charging cable

Get this for even less
Assessment takes 2 minutes and you’ll get an offer instantly. If the price is right, settle up your cart to make it official.
Like starting from . We’ll buy back your old tech for cash.


Galaxy S21 Ultra 5G - Unlocked's customer reviews


235 verified reviews in the last 6 months.

  • M

    Michael E.

    Purchased on February 2, 2024


    The Samsung S21 Ultra appears to be fine in the two weeks since we received it and was as promised. Ordering was easy and delivery was as expected. Our trade-in offer was much lower than we had anticipated ($25.00) for a phone in complete working order without problems. I have previously purchased certified, refurbished smartphones directly from Samsung and felt we received a much better & fairer trade-in offer. While the price of the S21 Ultra was cheaper from Back Market, I believe that I might have fared better buying from Samsung in terms of overall cost. I will research more closely when it's time for our next purchase.

    Reviewed in the United States on February 19, 2024

    Galaxy S21 Ultra 5G 128GB - Dark Gray - Unlocked
  • S

    Shawn N.

    Purchased on May 20, 2024


    The phone is amazing and just as I expected. It did have a small scratch on the front that is deep enough to see when the phone isn't on when I ordered the excellent version, but other than that it's great!! I would definitely recommend it to anyone looking to buy refurbished!

    Reviewed in the United States on June 4, 2024

    Galaxy S21 Ultra 5G 128GB - Dark Gray - Unlocked
  • G

    Gerald P.

    Purchased on March 10, 2024


    Trading in my beat-up S21Ultra with damaged screen for this excellent condition replacement enabled me to, in turn, take advantage of trade-in promotion at Samsung Store. My old phone was worthless for trade-in otherwise. The refurbisher who purchased my trade-in tried to claim that it didn't take a charge... but with my photos in hand, the Backmarket staff swiftly dealt with that. Be sure to take photos of live phone, and of each stage of packaging, so that Backmarket is able to support you in case of dispute. Great customer service!

    Reviewed in the United States on April 11, 2024

    Galaxy S21 Ultra 5G 128GB - Dark Gray - Unlocked
  • G

    Gene B.

    Purchased on February 29, 2024


    the whole experience was seamless and great! couldn't have asked for a better experience. I purchased S21 Ultra 256gb Unlocked. while I was hesitant about buying a refurbished device, then my device showed up and all the hesitance went right away! will purchase from again !

    Reviewed in the United States on March 21, 2024

    Galaxy S21 Ultra 5G 128GB - Dark Gray - Unlocked
  • J

    Jared R.

    Purchased on January 17, 2024


    The phone is great. It works perfectly, the camera is awesome and te phone's processing capabilities are in good condition. I always buy refurbished because it's cheaper and this product came on time and in great condition so, thank you!

    Reviewed in the United States on February 7, 2024

    Galaxy S21 Ultra 5G 128GB - Dark Gray - Unlocked
  • E

    Edward E.

    Purchased on December 15, 2023


    Delivery wason time and the phone arrived as described (S21 Ultra in good condition). Everything works fine, except the battery which lasts only half a day under little to moderate useage. From the descriptions of this model, I expected a full day of heavy useage to two days of light use on a fully charged battery. I know it's a used phone, but if the battery is this weak it should have been swapped in order to consider this a refurbished phone.

    Reviewed in the United States on January 1, 2024

    Galaxy S21 Ultra 5G 128GB - Dark Gray - Unlocked
  • K

    Kyle M.

    Purchased on May 27, 2024


    There was a scratch on the back by the camera, I give the quality of this refurbished device 4.5/5 stars. Everything else 💪 appears to be in good working order. This is a great phone for the price. The ultra that is. 12gb ram...super fast 🏃‍♂️

    Reviewed in the United States on June 9, 2024

    Galaxy S21 Ultra 5G 128GB - Dark Gray - Unlocked
See all 235 reviews

Reborn vs. brand new

Here’s what you help prevent on average by choosing a reborn smartphone over a brand new one.

171.1 lbs of CO2e

That's like driving an SUV from NYC to Chicago.

6.3 oz of e-waste

That’s around the weight of a baseball.

537.1 lbs of raw materials

That's like 20 dogs digging in your yard for a week.

20,341.2 gallons of water

That's like running a faucet for 3 days

Everything you ever wanted to know about the Galaxy S21 Ultra 5G - Unlocked

Galaxy S21 Ultra 5G 128 GB - Phantom Navy - Unlocked

Our partners are electronics experts who test and verify that each item is 100% functional before it leaves the workshop. This is the reason you benefit from a minimum 1-year warranty with the purchase of a refurbished device at Back Market.

Galaxy S21 Ultra 5G 128GB - Dark Gray - Unlocked

  • Color : Dark Gray
  • Screen size (inches) : 6.8
  • Model : Galaxy S21 Ultra 5G
  • OS : Android
  • Resolution : 1440x3200
  • Carrier compatibility : Unlocked
  • Storage : 128 GB
  • Memory : 12 GB
  • Network : 5G
  • Double SIM : No
  • Manufacturer Ref. : SM-G998U
  • Memory Card Slot : No
  • Verizon compatible : Yes
  • AT&T compatible : Yes
  • T-Mobile compatible : Yes
  • Release Year : 2021
  • Foldable : No
  • SAR head : 0.77
  • SAR body : 1.02
  • Series : Samsung Galaxy S
  • SIM card : Single-SIM + eSIM
  • Color (official name) : Phantom Navy
  • Product type : Refurbished
  • Brand : Samsung
  • Weight : 8 oz

Welcome to Back Market

The best prices for high-quality reborn tech by sellers we’ve checked and vetted. We don’t mind if you Google us.

Get to know us
  • 1-year warranty
  • Free standard shipping
  • Free 30-day returns
  • Friendly customer service
1 / 3.