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Galaxy S21 5G vs Galaxy S25

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Starting at

£167.39

£769 new

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Starting at

£393

£799 new

See options
Galaxy S21 5GStarting at £167.39See options
Galaxy S25Starting at £393See options
4.3/5 (16 reviews)
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In a nutshell

They share the same 6.2-inch screen size, the same 120Hz refresh rate and the same IP68 rating. The Galaxy S21 5G has the lower launch price. The Galaxy S25 counters with longer OS support until about 2032 (est.), more memory with 12GB of RAM and the newer Snapdragon 8 Elite for Galaxy chip.

At 128GB, the Galaxy S21 5G launched at £769 and the Galaxy S25 at £799.

Available models

Galaxy S21 5G

Capacity

Condition grades in stock

Excellent, Great, Good

Galaxy S25

Capacity

Condition grades in stock

Pristine, Excellent, Great, Good

Durability

Galaxy S21 5G 45/100
Galaxy S25 89/100

The Galaxy S25 should be supported for longer, with OS updates until about 2032 (est.) against about 2025 (est.) on the Galaxy S21 5G.

Software support:The Galaxy S21 5G should get OS updates until about 2025 (est.) and the Galaxy S25 until about 2032 (est.). That gives the Galaxy S25 the longer support window.

Frame:The Galaxy S21 5G has an aluminium frame and the Galaxy S25 an armour aluminium one.

Front glass:The Galaxy S21 5G has Gorilla Glass Victus on the front and the Galaxy S25 Gorilla Glass Victus 2.

Weight:The Galaxy S21 5G weighs 169g and the Galaxy S25 162g, so the Galaxy S25 is the lighter phone.

Released

2021
2025Newer

Updates until (est.)

2025
2032Supported for longer

Water resistance

IP68
IP68

Frame

Aluminium
Armour Aluminium

Weight

169g
162gLighter

Release date

29 January 2021
7 February 2025

Front glass

Gorilla Glass Victus
Gorilla Glass Victus 2

Dimensions

151.7 x 71.2 x 7.9 mm
146.9 x 70.5 x 7.2 mm

Biometrics

Ultrasonic fingerprint; Face recognition
–

Security updates until

2026
2032

Repairability

–
EU repairability class C

Performance

Galaxy S21 5G 60/100
Galaxy S25 94/100

The Galaxy S25 has the newer chip, the Snapdragon 8 Elite for Galaxy.

Chip:The Galaxy S21 5G runs the Exynos 2100 and the Galaxy S25 the Snapdragon 8 Elite for Galaxy. The Snapdragon 8 Elite for Galaxy is the newer chip, from 2025.

Memory:The Galaxy S25 has 12GB of RAM against 8GB on the Galaxy S21 5G, which helps keep more apps open in the background.

Storage:The Galaxy S21 5G launched in 128GB and 256GB and the Galaxy S25 in 128GB, 256GB and 512GB.

Chip

Exynos 2100
Snapdragon 8 Elite for Galaxy

RAM

8GB
12GBMore memory

Storage options

128GB, 256GB
128GB, 256GB, 512GB

AI features

–
Yes

Screen quality

Galaxy S21 5G 94/100
Galaxy S25 92/100

The same 6.2-inch size and the same 120Hz refresh rate on both.

Panel:The Galaxy S21 5G uses a Dynamic AMOLED 2X panel at 2400 x 1080 and the Galaxy S25 a Dynamic AMOLED 2X panel at 2340 x 1080.

Size:Both have the same 6.2-inch screen.

Smoothness:Both refresh at the same 120Hz.

Screen size

6.2"
6.2"

Screen type

Dynamic AMOLED 2X
Dynamic AMOLED 2X

Refresh rate

120Hz
120Hz

Resolution

2400 x 1080
2340 x 1080

Peak brightness

–
2600 nits (maker figure)

Camera

Galaxy S21 5G 42/100
Galaxy S25 70/100

The Galaxy S25 has the higher-resolution 50MP main camera.

Main camera:The Galaxy S25 has a 50MP main camera against 12MP on the Galaxy S21 5G, which leaves more detail to crop into.

Selfies:The Galaxy S25 has a 12MP selfie camera against 10MP on the Galaxy S21 5G.

Video:The Galaxy S21 5G records video at up to 8K 24fps and the Galaxy S25 at up to 8K 30fps.

Ultrawide:Both have the same 12MP ultrawide.

Main camera

12MP
50MPMore megapixels

Ultrawide

12MP
12MP

Telephoto

64MP
10MP

Optical zoom

–
3x

Front camera

10MP
12MPSharper selfies

Video recording

8K 24fps
8K 30fps

Battery

Galaxy S21 5G 65/100
Galaxy S25 67/100

Both have the same 4000mAh battery.

Wireless charging:For wireless charging, the Galaxy S21 5G supports Qi 15W and the Galaxy S25 Qi, Fast Wireless Charging 2.0.

Wired charging:Both charge at up to the same 25W over a cable.

Battery

4000mAh
4000mAh

Wired charging

25W
25W

Wireless charging

Qi 15W
Qi, Fast Wireless Charging 2.0

Video playback (maker)

–
Up to 29 hours

Connectivity

Galaxy S21 5G 100/100
Galaxy S25 88/100

5G

Yes
Yes

Port

USB-C
USB-C (USB 3.2 Gen 1)

Wi-Fi

–
Wi-Fi 7

SIM

–
Dual Nano-SIM or Nano-SIM + eSIM

Bluetooth

–
Bluetooth 5.4

Our verdict

Buy the Galaxy S21 5G if you want the lower launch price. Buy the Galaxy S25 if you want longer OS support until about 2032 (est.) and more memory with 12GB of RAM.

Buy the Galaxy S21 5G if

  • You want the lower launch price
Shop from £167.39

Buy the Galaxy S25 if

  • You want longer OS support until about 2032 (est.)
  • You want more memory with 12GB of RAM
  • You want the newer Snapdragon 8 Elite for Galaxy chip
Shop from £393

FAQs

The Galaxy S21 5G should get OS updates until about 2025 (est.) and the Galaxy S25 until about 2032 (est.). That gives the Galaxy S25 the longer support window.

Every Reboxed phone has a minimum of 80% battery health. If you want the closest thing to new, some phones offer our New Battery Upgrade, professionally installed before your phone is dispatched. If it's available, you'll see it on the product page.

Pristine, Excellent, Great and Good. Pristine has zero blemishes and at least 90% battery health. Good can show noticeable wear on the casing but works perfectly. Every grade is TechCheck certified and comes with a 12-month warranty.

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