Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstalliTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
The Samsung Galaxy A51 is a 2020 LTE smartphone with a 6.5-inch Super AMOLED display, a 4,000 mAh battery, four rear cameras, and microSD expansion. It remains a capable basic phone for calls, messaging, streaming, photography, and everyday apps, but its age matters: the standard A51 is not a 5G phone, it charges at 15 W rather than 25 W, and its official Android upgrade path ends with Android 13.
Before buying, repairing, or installing firmware, identify the exact model. The U.S. unlocked version is SM-A515U1; international versions such as SM-A515F can differ in RAM, SIM configuration, LTE bands, storage, and software availability.
Samsung Galaxy A51 specifications
The specifications below describe the U.S. unlocked model where Samsung reports a regional difference. International A51 variants are not identical.
Free tools Windows power users keep installed
One-click scans. No signup required.
| Feature | Specification |
|---|---|
| Display | 6.5-inch Super AMOLED; 6.3 inches within the rounded corners; 1080 × 2400 FHD+ |
| Processor | Octa-core, up to 2.3 GHz plus 1.7 GHz |
| Rear cameras | 48 MP main, 12 MP ultra-wide, 5 MP macro, and 5 MP depth |
| Front camera | 32 MP, f/2.2 |
| Video | Up to 4K UHD at 30 frames per second; HD slow motion at 240 fps |
| Storage | 128 GB on the U.S. unlocked model, with approximately 105.9–106.0 GB available to the user |
| microSD | Supports cards up to 512 GB |
| RAM | 4 GB in the U.S. unlocked model; some markets received 4 GB, 6 GB, or 8 GB versions |
| Battery | 4,000 mAh typical capacity |
| Charging | 15 W wired Fast Charging over USB Type-C |
| Wireless connections | Dual-band 802.11ac Wi-Fi, Bluetooth 5.0, NFC, GPS, GLONASS, and Galileo |
| Headphone port | 3.5 mm |
| Dimensions and weight | 6.24 × 2.89 × 0.31 inches; 6.07 ounces for the U.S. unlocked model |
Display and everyday performance
The A51’s Super AMOLED panel is one of its strongest features. Its 1080 × 2400 resolution produces a sharp image for web pages, video, photos, and reading, while AMOLED contrast gives blacks a deeper appearance than a conventional LCD. The screen measures 6.5 inches across the full rectangle, although Samsung lists 6.3 inches when the rounded corners are excluded.
#1 Best Overall
- Ships in non-retail box; generic charger and USB Cable only.
- No any other accessories included.
- This device is GSM unlocked. GSM Compatible, Not compatible with : Any CDMA network like : Verizon, Virgin Mobile US or Boost. Network bands in regions may be different depending on the mobile operator and your location. Available storage is less and subject to change due to device software updates and apps usage.
- it's only support Wi-fi calling for Sprint. Not other carrier.
The octa-core processor is adequate for ordinary use but should not be judged like a current mid-range chipset. Messaging, navigation, music, social apps, and video playback are its natural workload. Heavy games, extensive multitasking, and newer demanding apps may expose the limits of the processor and the 4 GB RAM configuration found in the U.S. model.
Cameras: what the four rear lenses do
The rear camera system is a combination of different camera types, not four equivalent high-resolution cameras:
- 48 MP main camera: the general-purpose camera for most photographs.
- 12 MP ultra-wide camera: captures a wider field of view for landscapes, groups, and interiors.
- 5 MP macro camera: intended for close-up subjects.
- 5 MP depth camera: assists portrait-style background separation rather than serving as a normal standalone camera.
The front-facing camera is 32 MP. Video recording reaches 4K UHD at 30 fps, and slow motion is available at up to 240 fps in HD. Camera results depend heavily on lighting; the megapixel numbers alone do not make the A51 comparable to newer phones with larger sensors and more advanced image processing.
Battery, charging, and ports
The phone has a 4,000 mAh typical battery and 15 W wired Fast Charging through its USB Type-C port. A commonly copied specification says that the A51 supports 25 W charging, but that figure belongs to other Samsung models and is not the standard A51’s charging rate.
The A51 does not have built-in wireless charging. A third-party wireless-charging receiver can be added, but that is an accessory and may occupy the USB-C port or require a compatible case. Samsung also does not list an IP water- or dust-resistance rating for the phone, so it should not be treated as waterproof or IP-rated.
Storage, SIM cards, and regional model differences
Although the U.S. unlocked A51 is advertised with 128 GB of storage, only about 105.9–106.0 GB is available before personal files are added. Android, One UI, and preinstalled applications use the remaining space. A microSD card of up to 512 GB can provide additional room for photos, videos, and other supported files.
Rank #2
- Network Compatibility: This device is GSM unlocked and will work with T-Mobile, AT&T, Not compatible with Cricket and any other CDMA network
- Refurbished Condition: May have minor scuffs or scratches
- Package Contents: Ships in non-retail box with generic charger and USB Cable only, no other accessories included
- Warranty and IMEI Status: Clean IMEI with 90 days store warranty
- Carrier Restrictions: Not compatible with Cricket and Verizon networks
Do not assume that every A51 has the same tray. Samsung’s global launch information described a dual-SIM, three-slot arrangement for some markets, while the U.S. unlocked specification lists SIM 1 + microSD. RAM, storage, colors, processors, SIM arrangements, and LTE bands can also vary.
Check the model before buying imported stock or downloading firmware:
- Open Settings.
- Tap About phone.
- Record the complete model number, such as SM-A515U1 or SM-A515F.
You can also display the IMEI by dialing *#06# where supported. An imported SM-A515F may be unlocked yet still lack LTE bands or carrier certification needed for reliable service in the United States.
Is the Galaxy A51 5G?
No. The standard Galaxy A51 is an LTE/4G phone. Galaxy A51 5G is a separately named model, not an alternate software mode for the regular A51. Samsung’s U.S. unlocked specification lists LTE bands and no 5G radio.
This distinction matters when purchasing a used phone. A listing that says “A51 5G” is referring to different hardware. Confirm the model number and the network specifications rather than relying only on the seller’s title or a photograph.
Android and One UI update history
The A51 originally shipped with Android 10. Samsung subsequently provided Android 11, Android 12, and Android 13 with One UI 5, followed by One UI 5.1 for supported regional variants. Samsung’s policy of up to three Android OS upgrades accounts for Android 11 through Android 13; the A51 was not included for later Android generations under that policy.
Rank #3
- Introducing the NEW A-Series: the features you’ve been waiting for in your unlocked cell phone. Take crisp pics with the 48MP quad camera. Immerse yourself in a spacious high definition screen, powered by a long-lasting, fast charging battery.
- Crisp. Colorful. Captivating. Dive into edge-to-edge color with an expansive 6. 5” Infinity-O Display featuring a Super AMOLED screen that brings cinematic clarity right to your fingertips.
- Pro-grade shots in just a snap: From epic landscape shots and dramatic portraits, to macro angles that reveal intricate textures and detail, this impressive quad camera has a lens for whatever inspires you.
- Smooth, stable shots: Take remarkably smooth video of fast-moving action in crisp, UHD quality. Its top-notch stability makes photos and videos look super smooth with minimal blur.
- Verizon Branded. Works with Verizon and unlocked to work with most GSM carriers.
Update timing depends on the model, country, carrier, and firmware region. As of August 9, 2026, Samsung’s official SM-A515F update-history page lists build A515FXXU8HWK1, based on Android 13, with a page entry dated February 26, 2025 and a listed security-patch level of August 1, 2023. That information applies to that specific model and region; it is not evidence that every A51 received the same release.
How to check for a Galaxy A51 update
- Open Settings.
- Tap Software update or System updates.
- Select Download and install, Check for system updates, or Check for software updates, depending on the software version.
- Follow the instructions if an update is offered.
To see the installed Android version, One UI version, and security patch, open Settings > About phone > Software information.
A carrier may require Wi-Fi, and the phone may need several sequential updates rather than jumping directly to the newest available release. The phone cannot be used, including for emergency calls, while an update is installing. Keep it charged and avoid interrupting the process.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsUpdating with Samsung Smart Switch
If no over-the-air update appears, Samsung’s supported computer method is Smart Switch:
- Install Smart Switch on a Windows PC or Mac.
- Connect the A51 with a USB cable.
- Open Smart Switch and wait for it to detect the phone.
- Choose Update if that option is displayed.
- Leave the cable connected and do not use the phone until the installation completes.
Smart Switch offers firmware appropriate to the detected device and available release. It does not guarantee that an update exists for every regional variant.
Common Galaxy A51 problems and what they mean
| Problem | Likely explanation or next step |
|---|---|
| No update appears | The device may use a different carrier, model, or firmware region. Check the complete model number under Settings > About phone. |
| Update fails or stops | Use Wi-Fi if required, charge the phone, free internal storage, retry, or use Smart Switch. Do not disconnect the USB cable during a Smart Switch update. |
| Less than 128 GB is available | This is expected. The operating system and preinstalled software account for roughly 22 GB of the advertised capacity on the U.S. model. |
| Imported phone has weak or missing service | Its LTE bands or carrier support may differ from those of the local version. Unlocked does not mean universally compatible. |
| Phone gets wet | The A51 has no official IP rating listed by Samsung. Power it down and seek appropriate repair advice rather than assuming water resistance. |
Should you still buy a Galaxy A51?
The A51 can make sense as an inexpensive used phone when the price is low, the battery is healthy, and the exact model works on the intended carrier. Its AMOLED display, headphone jack, microSD slot, 4K video, and expandable storage remain useful.
It is a weaker choice when long-term security support, 5G, fast charging, water resistance, or demanding performance are priorities. Before purchasing, verify the model number, IMEI status, LTE compatibility, battery condition, screen burn-in, charging port, cameras, and whether the phone can receive the updates available for that region.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
FAQ
Is the Samsung Galaxy A51 a 5G phone?
No. The standard Galaxy A51 supports LTE/4G only. The Galaxy A51 5G is a separate model with different hardware.
What is the maximum charging speed of the Galaxy A51?
The standard Galaxy A51 supports 15 W wired Fast Charging. It does not natively support 25 W charging or built-in wireless charging.
What Android version does the Galaxy A51 support?
The A51 shipped with Android 10 and received Android 11, Android 12, and Android 13 with One UI 5. One UI 5.1 was also released for supported variants. Its official three-generation upgrade policy does not cover later Android generations.
How do I identify my Galaxy A51 model?
Go to Settings > About phone and check the complete model number. Examples include SM-A515U1 for the U.S. unlocked model and SM-A515F for an international variant. You can also dial *#06# to display the IMEI where supported.
Recommended Free Tools
The Bottom Line
The Samsung Galaxy A51 is still a practical budget phone if you need an AMOLED screen, a headphone jack, microSD expansion, and basic everyday performance at a used-phone price. Treat it as an LTE-era device, however: charging is limited to 15 W, there is no official IP rating or wireless charging, regional specifications differ, and Android 13 is the end of its planned major Android upgrade path.
Quick Recap
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.
