Compare Samsung S21: S21, S21+ and Ultra buying guide

Updated: 2026-08-12 · Tech and mobiles

A smartphone on a box showing a software update screen, creating a tech-focused scene. — Foto: Andrey Matveev / Pexels

Quick answer: Compare Samsung S21 by matching your size and camera needs: the 6.2-inch S21 for pocketability, the 6.7-inch S21+ for battery, or the S21 Ultra for 10x optical zoom and QHD display. In the EU market check Exynos 2100 units, local 5G bands, battery health on used stock and how many Android upgrades remain for that serial batch.

Key points

Base S21 has a polycarbonate back; Plus and Ultra use glass builds.
European units ship with Exynos 2100 rather than the US Snapdragon 888.
S21 Ultra adds a 108 MP main sensor and periscope 10x zoom module.
Samsung pledged four Android OS generations for the S21 family.
Confirm eSIM and 5G support with your Spanish operator before purchase.

Context and criteria

Searching compare Samsung S21 usually means weighing a 2021 flagship against a newer mid-range Galaxy or a used iPhone. Do not line up the compact S21 against the Ultra as if they target the same buyer: battery capacity, zoom hardware and chassis materials diverge sharply despite shared One UI software.

What to compare in detail

Official EU distribution matters for warranty repairs and Samsung Members battery diagnostics. Refurb sellers in Spain should disclose cycle count or minimum health percentage; walk away from units with screen burn-in or swollen batteries, common risks on five-year-old AMOLED stock.

Key variables

All three models offer 120 Hz Dynamic AMOLED panels, yet only the Ultra defaults to QHD+ without the battery trade-off users notice on smaller variants. Mobile gamers should test thermals after extended sessions because the compact chassis throttles sooner under sustained load.

Practical tips

Before paying, compare Samsung S21 pricing against refurbished S22 or S23 listings: the gap is sometimes narrow when you factor remaining software support. Request IMEI clearance from carriers, verify dual-SIM behaviour if you travel, and test ultrawide autofocus in low light.

Comparison table

Model	Display	Battery
Galaxy S21	6.2" FHD+ 120 Hz	4000 mAh
Galaxy S21+	6.7" FHD+ 120 Hz	4800 mAh
Galaxy S21 Ultra	6.8" QHD+ 120 Hz	5000 mAh
EU chipset	Exynos 2100	5 nm, sub-6 5G

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FAQ

Which S21 is smallest when I compare Samsung S21 sizes?

The standard Galaxy S21 at 6.2 inches is the most pocketable. S21+ and Ultra add weight and camera bulk, especially the Ultra module.

Is the S21 Ultra worth it over the Plus?

Choose Ultra if you rely on 10x optical zoom or 8K video. The S21+ covers most daily use with a larger screen and lower refurbished price.

Do S21 phones still get security updates in Europe?

Samsung included the S21 line in its extended update programme. Check Settings on the exact handset to see the latest One UI version installed.

Does Exynos vs Snapdragon matter for EU buyers?

Spanish retail units use Exynos 2100. US imports with Snapdragon 888 differ in efficiency and modem bands and may lack full local warranty.