Head to head
Samsung Galaxy S26vsSamsung Galaxy S21
The short answer
Choose the Galaxy S26 for peak brightness, more base storage and video playback time. The Galaxy S21 wins no row by a gap you’d notice. The Galaxy S21 is £110 cheaper at UK RRP (£769 against £879). The Galaxy S21’s security updates ended in February 2026; the Galaxy S26 gets them until February 2033.
- Released
- 2026-03-06endoflife.date, retrieved 2026-08-20
- Price
- £879Samsung Newsroom UK — Galaxy S26 series, retrieved 2026-08-20
- Security updates until
- 2033-02-28Samsung UK spec API — Galaxy S26, retrieved 2026-09-22
- Released
- 2021-01-29endoflife.date, retrieved 2026-08-20
- Price
- £769Samsung Newsroom UK — Galaxy S21 5G and S21+ 5G, retrieved 2026-08-20
- Security updates until
- 2026-02-21endoflife.date — Samsung mobile, retrieved 2026-09-06
3 wins for Galaxy S260 wins for Galaxy S211 gap borderline3 differences you won’t notice£110 apart at RRP
Verdict: Galaxy S26 ahead on 3 rows, Galaxy S21 on none
On the makers’ figures and the named third-party sources, the Galaxy S26 wins on peak brightness (2,600 nits against 1,300 nits, both from GSMArena), storage (base) (256 GB against 128 GB) and claimed video playback (30 h against 20 h). One gap is borderline, a difference most people would not notice: RAM (12 GB against 8 GB) for the Galaxy S26. The differences in weight, display size and battery capacity are below the thresholds you would notice. Both state the same refresh rate, fast charging and wireless charging. The other 37 rows have no threshold or no direction to judge by, so nobody wins them.
True to scale
Outlines from each maker’s published dimensions, drawn to scale. Corner rounding is our drawing convention, not a measurement.
Specifications
A win is marked only where the figures can be ranked and the gap is one you could notice. A row the site has no threshold for says whether the two differ, and that it is not ranking them. = marks the same figure on both, ≠ not ranked a difference with no ranking. Every figure carries its source.
Body
Display
Platform
Memory
Camera
Battery
Connectivity
Benchmarks
4 attributes neither phone has a sourced figure for
Typical brightness · HDR peak brightness · OS versions supported · Google Mobile Services. Rows appear as sources are cited — a gap in our data, not a statement about either phone.
Questions
Is the Galaxy S26 better than the Galaxy S21?
On the figures, the Galaxy S26 is ahead wherever there is a gap you’d notice: peak brightness, 2,600 nits against 1,300 nits (both GSMArena), storage (base), 256 GB against 128 GB (both Samsung Newsroom UK) and claimed video playback, 30 h against 20 h (both Samsung UK). The Galaxy S21 wins no row by such a gap. That is a count of rows, not an overall score.
Which has the better battery?
The Galaxy S26, by a gap you’d notice: claimed video playback, 30 h against 20 h (both Samsung UK). The Galaxy S26 is ahead on paper, but not by a gap you’d notice: battery capacity, 4,300 mAh against 4,000 mAh (both Samsung Newsroom UK).
Which is lighter?
The Galaxy S26 is lighter on paper, but not by a gap you’d notice: weight, 167 g against 169 g (both Samsung Newsroom UK).
Which has the brighter screen?
The Galaxy S26, by a gap you’d notice: peak brightness, 2,600 nits against 1,300 nits (both GSMArena).
Which gets updates for longer?
The Galaxy S21’s security updates ended in February 2026; the Galaxy S26 gets them until February 2033. Sources: dates from Samsung UK spec API and endoflife.date.
Which is cheaper?
The Galaxy S21 is £110 cheaper at UK RRP (£769 against £879). Prices from Galaxy S26: Samsung Newsroom UK; Galaxy S21: Samsung Newsroom UK.
Other comparisons
The pairs a buyer of either phone would also weigh. Any two phones in the catalogue can be compared from the chooser.