This is the English edition of a review from my Japanese YouTube channel, iestaLife. I review gadgets from my home studio in Japan, so product links go to Amazon Japan.
Quick take
I bought four small 20 W USB-C chargers on Amazon Japan: Anker Nano Charger 20W, Buffalo, Yamazen and a little-known brand called viviber. All four charged an iPhone at roughly 19 W, so speed is not the deciding factor. Weight, folding plugs and build quality are. The surprise winner for travel was Yamazen: foldable, 36 g and nicely made.
What I tested
- Yamazen 20W USB-C charger (Japanese brand; ¥1,264 list, ¥1,080 when I bought it)
- Anker Nano Charger 20W (¥1,690)
- Buffalo 20W USB-C charger (Japanese brand, GaN; ¥1,280)
- viviber 20W charger (¥568)
- Charging an iPhone from 68% through a USB power meter, plus weighing each charger
What I found
- Speed: all four reached about 19 W. Yamazen and viviber went slightly over 19 W; Anker and Buffalo sat in the high 18s.
- Yamazen: far better finish than I expected, matte black with a glossy band, foldable plug, 36 g. My pick for a bag.
- Anker Nano: the most premium design, with a clear outer shell and many colors, plus temperature monitoring. The plug does not fold, so I see it as a home charger.
- Buffalo: plain white with a tiny 20W label, foldable plug, good plastic. The heaviest at 43.1 g and a little larger than Yamazen.
- viviber: it works, but it is large, feels hollow at 31.9 g and the plastic feels cheap. I would not choose it as my main travel charger.
| Yamazen | Anker Nano | Buffalo | viviber | |
|---|---|---|---|---|
 |  |  |  | |
| Price* | ¥1,080 (list ¥1,264) | ¥1,690 | ¥1,280 | ¥568 |
| Weight | 36 g | 33.1 g | 43.1 g | 31.9 g |
| Output | Over 19 W | 18 to 19 W | Close to 19 W | Over 19 W |
*Prices at the time of recording.
Who it is for
- Travel: Yamazen
- Home, bathroom or other clean white spaces: Anker Nano
- A charger that blends in without a visible logo: Buffalo
- Buying many cheap chargers: viviber
Yamazen and Buffalo are Japanese brands and may be hard to find outside Japan. Anker Nano Charger 20W is widely available.
The video is in Japanese. It shows each charger up close, which helps more than the product photos.
Limitations
I tested one iPhone charge per charger for a short time, and I did not test long-term durability or heat. These chargers use Japanese plugs (Type A).
Products
Yamazen 20W USB-C charger: on Amazon Japan
Anker Nano Charger 20W: on Amazon Japan
Buffalo 20W USB-C charger: on Amazon Japan
viviber 20W charger: on Amazon Japan
The Amazon Japan links above are affiliate links. As an Amazon Associate, I earn from qualifying purchases. Check the listing for the exact model, current price and shipping availability in your region.
More reviews in English
All Chargers & Cables (29) →Browse all English reviews →
This review is also available in Japanese.