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Samsung Galaxy S21 Ultra 5G

Carrier:

Storage:

Cosmetic Condition:

Functionality:

Accessories included:

The Samsung Galaxy S21 Ultra 5G launched in 2021 as Samsung's top-tier flagship of that year, built for buyers who wanted the biggest screen, the longest camera zoom, and S Pen support without stepping up to the Note line. In the US it carries the model number SM-G998U, sold through AT&T, T-Mobile, and Verizon, plus an unlocked retail version. Years later, the quad rear camera, the 120Hz QHD+ display, and factory support for the S Pen keep this phone in steady demand on the resale market, particularly in the higher storage tiers. Pick your carrier, storage, and condition above for a live cash offer, or see how the process works to understand inspection and payout timing before you ship anything. If you have more than one device to move, sell your smartphone through Gadget Salvation and compare offers across the full lineup we buy.

Confirm you have the Galaxy S21 Ultra 5G

Open Settings → About phone → Model number. This is the fastest reliable check, and it also confirms your storage tier under Settings → About phone → Storage. If you cannot power the phone on, the model number is printed on the original box and on the SIM tray sticker.

SM-G998U / SM-G998U1

  • US retail and carrier variant, sold through AT&T, T-Mobile, and Verizon
  • Unlocked retail units may show SM-G998U1 instead of SM-G998U; both use identical hardware
  • Qualcomm Snapdragon 888 processor across every US unit, regardless of carrier
  • 5G-capable on both sub-6GHz and, on some carrier variants, mmWave bands

Prefer a visual check? The S21 Ultra has a rear camera housing that blends directly into the aluminum frame instead of sitting in a separate square island, a 6.8-inch curved display, and a matte glass back. If the phone has a small S Pen silo cut into the bottom edge, it is not this model.

Core hardware configurations

Processor

  • Qualcomm Snapdragon 888, 5nm, same chip across all US storage and carrier variants
  • Paired with the Adreno 660 GPU

Memory

  • 12GB RAM on the 128GB and 256GB configurations
  • 16GB RAM on the 512GB configuration
  • Soldered, not upgradable after purchase

Storage

  • 128GB, 256GB, or 512GB, all UFS 3.1
  • No microSD slot on this generation
  • Higher storage tiers move resale value the most, since capacity cannot be added later

Cameras

  • 108MP main wide sensor
  • 10MP telephoto with 3x optical zoom
  • 10MP periscope telephoto with 10x optical zoom
  • 12MP ultrawide, plus a 40MP front camera

Display & audio

Display

6.8-inch Dynamic AMOLED 2X panel at QHD+ resolution with an adaptive refresh rate up to 120Hz. The front and back are covered in Gorilla Glass Victus.

Audio

Stereo speakers tuned by AKG with Dolby Atmos support. There is no headphone jack, so audio out runs through USB-C or Bluetooth.

Security

Ultrasonic fingerprint sensor built into the display, alongside face recognition using the front camera.

Ports & connectivity

This is a single-port phone, so most of the identifying detail is in the radios rather than the edges.

Wired
  • USB-C (USB 3.2)
  • No headphone jack
Wireless
  • 5G (sub-6GHz, mmWave on select carrier variants)
  • Wi-Fi 6E
  • Bluetooth 5.0
  • NFC and Ultra Wideband (UWB)

108MP main camera 10x optical zoom S Pen support 120Hz QHD+ display IP68 rated Ultrasonic fingerprint 5000mAh battery

Battery, build & more

Battery

5000mAh with 25W wired fast charging, 15W wireless charging, and reverse wireless charging for accessories. A charger is not included in the retail box.

Finishes

Phantom Black and Phantom Silver were the widely stocked colors, with Phantom Titanium, Navy, and Brown sold as Samsung.com exclusives.

Software

Shipped on Android 11 with One UI, and eligible for several years of Android version updates and ongoing security patches.

Known issues

Some units from this Galaxy S21 generation have been reported with a faint green line display defect, generally tied to the display panel rather than to physical damage. It affects a subset of devices, not the model as a whole.

Frequently asked questions

01 How do I find the model number or exact configuration?
Go to Settings → About phone → Model number, which will read SM-G998U or SM-G998U1. The same screen shows your storage tier, and Settings → Connections → Mobile networks will show which carrier the phone is provisioned for, if any. This is the quickest way to match your device to the right configuration above before you request a quote.
02 How do I tell it apart from the Galaxy S21+ 5G?
Check the screen size and the camera housing. The S21 Ultra has a 6.8-inch display versus the S21+'s 6.7-inch, and its rear camera array carries four lenses, including a visible periscope telephoto module, while the S21+ has three. The Ultra's camera bump also blends into the frame more sharply. If Settings → About phone shows model number SM-G996U, that is the S21+, not this listing.
03 Can I sell it with damage, a weak battery, or a locked account?
Yes, in most cases. A cracked screen, a battery that drains fast, or a phone that will not power on can still be sold; the condition picker above adjusts the offer to match. What cannot ship is a phone still tied to a Samsung account or Google account with Find My Mobile or Factory Reset Protection active, since a locked phone cannot be tested or resold. Remove your accounts and confirm the lock screen shows no owner information before you send it in.
04 What raises the trade-in value the most?
Storage tier and carrier status move the offer the most. A 512GB unlocked phone in good cosmetic condition consistently sits above a 128GB carrier-locked one, since unlocked phones resell to a wider market. Beyond that, an original box, charging cable, and an undamaged screen and back glass all help, as does a battery that still holds a reasonable charge through a normal day.
05 How do I erase it and remove my accounts, and how do I get paid?
Back up anything you want to keep, then go to Settings → General management → Reset → Factory data reset. Before that, remove your Google account under Settings → Accounts and backup → Manage accounts, and turn off Find My Mobile under Settings → Biometrics and security → Find My Mobile so Factory Reset Protection does not lock the phone for its next owner. Also remove the SIM card if you are keeping your number. Once it is wiped, ship it to us free with insured shipping, and we pay by PayPal, Venmo, Zelle, CashApp, or check after testing confirms the condition you reported. Full details are in our data erasure protocols.