Anker 511 Charger (Nano Pro 20W) is 53% smaller by volume.
Anker does not publish how it divides power between ports, so a like-for-like comparison stops there.
Samsung is the cheaper watt: 0.33 €/W against 0.75 €/W.
Size, true to scale
front and side, one scale
20
30×30×30 mm 26 cm³ · 31 g
38×22×67 mm 56 cm³ · 52 g
Solid block is the face you see in the socket; the outline next to it is depth.
Power by situation
bars share one scale · 25 W
One device, best port
20 W
25 W
What a laptop gets when nothing else is plugged in.
Two devices at once
not published
not published
The best published pair, which is rarely an even split.
Three devices at once
not enough ports
not enough ports
Everything plugged in together.
Port layouts differ, so we compare what you would do with the charger, not port pairs. Each row takes the best published combination for that situation.
Field by field
Anker
Samsung
Total output
20 W
25 W
Ports
1×C
1×C
Volume
smaller is better
26 cm³
56 cm³
Weight
smaller is better
31 g
52 g
Power density
0.77 W/cm³
0.45 W/cm³
PPS
No
Yes
EPR
over 100 W
No
No
Folding plug
No
No
Price per watt
net of VAT
0.63 €/W
0.28 €/W
Documentation
9.0/10
8.8/10
marks the better value in that row. Ties, missing data and class differences get no mark.