Review · Apple · Phone class
Apple 20W USB-C: completely honest at 20W, and nothing beyond it.
Apple publishes two output rails for the A2305 and no others. Everything this adapter can and cannot do follows from those two lines.
The published specification
Built from the printed output profile, Apple's device charging documentation and US certification records — the basis on our disclosure page. No stopwatch data, no score, no price.
| Item | Specification | What it means in use |
|---|---|---|
| Rated output | 20W | Peak power, higher rail, single device |
| Output rails | 9V/2.22A and 5V/3A | Two fixed PD rails — no 15V, no 20V, no programmable band |
| Ports | 1× USB-C | One device at a time |
| Protocol | USB-C PD, fixed rails | No PPS, so no Samsung Super Fast Charging 2.0 |
| Form factor | Square brick, fixed US prongs | Prongs do not fold and are not removable |
| In the box | Adapter only | No USB-C cable; budget for one |
Two rails is the entire electrical story. Any device peaking at 9V — every iPhone since the iPhone 8 — gets everything this adapter has. One wanting 15V or 20V finds neither, drops to 9V and charges at 20W however large its battery: USB-C Power Delivery explained.
What it is genuinely good at
It is the reference brick: Apple's "up to 50% in around 30 minutes" iPhone claim is measured against a 20W-class adapter. The profile is boring in the best sense — two fixed rails, nothing that degrades by month 30. It is correctly sized for AirPods cases, the Watch puck, a 10th-generation iPad and every current iPhone, and over-serving costs nothing: a 5W accessory draws exactly 5W.
Where it falls short, and who should skip it
The fixed prongs are the limitation nobody lists: they do not fold and take no Apple duckhead blade, so this brick cannot join the World Travel Adapter Kit — abroad you need a plug adapter that swallows the whole US body.
The missing rails matter more, and the table below names who loses. Skip it if you own an iPhone 17, an iPad Air or Pro, any Galaxy, or want one brick for bag and nightstand — a 30W-class GaN with folding prongs and four rails does strictly more in a smaller body: 30W adapters.
Which devices it actually serves at full speed
| Device | Peak it requests | Served at full speed? |
|---|---|---|
| iPhone 15 / 16 | 20–27W | Yes; Pro Max finishes later than on 30W |
| iPhone 17 lineup | 40W sustained | No — see the 40W Dynamic review |
| iPad (10th / 11th gen) | ~20W | Yes, exact match |
| iPad Air / iPad Pro | 30W+ | No — capped at 20W |
| MacBook Air M-series | 30W minimum | No — trickle only |
| Galaxy S25 / S25 Ultra | 25W / 45W with PPS | No — fixed PD, mid-teens of watts |
| Nintendo Switch docked | 15V/2.6A | No — no 15V rail here |
The three adapters worth comparing it against
- 20W
Apple 20W USB-C Power Adapter
Bought for availability and the returns counter, not the spec sheet.
- Rated output
- 20W
- Rails
- 9V/2.22A, 5V/3A
- Ports
- 1× USB-C
- Plug
- Fixed prongs
- 30W
Anker Nano 30W
Single-port GaN with the 15V and 20V rails Apple omits.
- Rated output
- 30W class
- Ports
- 1× USB-C
- Plug
- Folds flat
- Tech
- GaN
- 20W
Amazon Basics 20W USB-C
Like-for-like profile and certification. Brand and returns differ.
- Rated output
- 20W class
- Ports
- 1× USB-C
- Protocol
- USB-C PD
Verdict
Buy it if you charge an iPhone and only an iPhone and want the brick Apple's own charge-time figures describe. Buy a 30W GaN if it must also cover a tablet or a second device — two more rails, folding prongs, smaller body.
Related reading
FAQ
Does the Apple 20W adapter fast-charge an iPhone?
Yes. Fast charging on iPhone means 20W or more over USB-C PD, and the 9V/2.22A rail delivers exactly that.
Is a third-party 20W adapter electrically the same?
If its profile lists 9V/2.22A and 5V/3A and it carries a UL or ETL mark, yes. Apple sells availability and returns, not more output.
Why does my Galaxy charge slowly on this adapter?
There is no PPS profile. Super Fast Charging needs a programmable voltage band; without one the phone falls back to fixed PD.
Can I leave an iPhone on it overnight?
Yes. The phone tapers current itself as it approaches full; the adapter supplies only what is requested.