No. The Samsung Galaxy S21 5G has no microSD or other external memory-card slot, so a card cannot expand its in-phone storage. Samsung’s UK specifications also list no external memory for the Galaxy S21+ 5G and S21 Ultra 5G.
Which Galaxy S21 storage capacities are available?
Samsung lists the unlocked Galaxy S21 5G with 128GB or 256GB of built-in storage. Availability can vary by market, model and carrier, so check the specification for the exact device you are considering.
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The stated capacity is not all available for your files: the operating system and device software use some space. Samsung notes that actual user memory can vary by operator and after software upgrades.
Does the same memory-card answer apply to the S21+ and S21 Ultra?
Yes. Samsung UK’s support table lists the Galaxy S21 5G, S21+ 5G and S21 Ultra 5G as having no external memory. The table was updated 29 May 2026 and warns that its specifications apply to UK and Ireland models and may differ by region. If you have a carrier-branded or non-UK model, confirm its exact model specification with Samsung for your market.
#1 Best Overall
- Display: 6.2" AMOLED display with 120Hz refresh rate and 1300 nits brightness for vivid visuals and smooth scrolling.
- Camera: Rear dual camera system with 64MP main and 12MP ultrawide lenses for stunning photos and videos.
- Memory: 128GB internal storage and 8GB RAM for plenty of apps and files.
- Connectivity: 5G capable with support for GSM, CDMA, and Wi-Fi networks.
- Battery: 4000mAh battery provides all-day power for your daily needs.
What to consider when choosing S21 storage
Because the S21 has no card slot, choosing between storage variants matters if you expect to keep many photos, videos, apps or other files on the phone. Compare the space you expect to need with the capacity available for the specific model, bearing in mind that usable space is lower than the advertised total. Samsung’s listed unlocked base-model choices are 128GB and 256GB; local carrier and regional availability may differ.
If you already own an S21, a microSD card will not work as an in-phone storage upgrade. Backing up files or moving them off the phone are alternatives to keeping everything in its built-in storage, but they do not add expandable internal storage.
Quick Recap
Best Value
- Android 11 | One UI 3.1 | Octa-core | 128GB | 8GB | Adreno 660
- Dynamic AMOLED 2X, 120Hz, HDR10+ display | Gorilla Glass | 6.7 inches | 1080 x 2400
- Wi-Fi 802.11 a/b/g/n/ac/6, dual-band| GPS | Wi-Fi Direct, hotspot | Bluetooth 5.0 | USB Type-C 3.2
- 12 MP Camera | LED Flash | 1080p | Speaker
- 6.36 x 2.98 x 0.31 | 7.05oz | Single SIM | GSM, HSPA, LTE, CDMA
Rank #4
- This Phone Is Unlocked And Compatible With Any Carrier Of Choice On Gsm And Cdma Networks (E.G. At&T, T-Mobile, Sprint, Verizon, Us Cellular, Cricket, Metro, Tracfone, Mint Mobile, Etc.).
- When You Receive The Phone, Insert A Sim Card From A Compatible Carrier. Then, Turn It On, Connect To Wi-Fi, And Follow The On Screen Prompts To Activate Service.
- The Device Does Not Come With Headphones Or A Sim Card. It Does Include A Charger And Charging Cable That May Be Generic.
- Tested For Battery Health And Assured To Have A Minimum Battery Capacity Of 80%.
Rank #3
- This pre-owned product has been professionally inspected, tested and cleaned by Amazon qualified vendors.
- This product is in "Excellent condition". The screen and body show no signs of cosmetic damage visible from 12 inches away.
- This product will have a battery that exceeds 80% capacity relative to new.
Rank #2
- The Galaxy S21 FE sports a sleek polycarbonate back with a premium matte finish that resists fingerprints and feels smooth in hand, giving it a stylish yet practical design.
Samsung Galaxy S21 storage at a glance
| Model | External memory | Listed built-in storage |
|---|---|---|
| Galaxy S21 5G | None, according to Samsung UK | 128GB or 256GB for the unlocked model listed by Samsung |
| Galaxy S21+ 5G | None, according to Samsung UK | Not stated in the cited compatibility table |
| Galaxy S21 Ultra 5G | None, according to Samsung UK | Not stated in the cited compatibility table |
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
