Phone Chargers and Power Adapters
A charger is the accessory most people buy first, because the phone box rarely holds one. This page shows how to read the numbers, what certification can and cannot tell you, and where the main trade-offs are. We do not test chargers, so we do not name brands or models, and we show no prices.
How many watts does my phone charger need?
It needs to meet the figure your maker publishes for your phone; more is allowed, less is slower. Samsung says your device automatically chooses the best supported charging speed when plugged into a higher-rated charger, so a bigger adapter is a ceiling, not a push. The wattage guide collects every figure we have verified.
| Phone family | What the maker publishes | Source |
|---|---|---|
| Samsung Galaxy, Super Fast Charging | A 25W or 45W Samsung-approved adapter, on select devices | Samsung |
| iPhone, wired fast charge | A claim, not a wattage: the iPhone 17 reaches up to 50% in 20 minutes with a 40W adapter or higher and a USB-C cable | Apple |
| iPhone, MagSafe up to 25W | A 30W or greater adapter rated 15V/2.0A or higher | Apple |
| iPhone, MagSafe up to 15W | A 20W or greater USB-C adapter | Apple |
| Library phones with a published wired figure | 25W to 68W (16 phones from Samsung and Motorola) | Maker spec pages |
| Library phones with no published wired figure | 25 of 41, so we leave the wattage blank | Our count |
Read the exact row for your model on its phone page or brand hub. Apple’s MagSafe page differs by model, and the iPhone Air, 16 and 16 Pro reach less than 25W.
Does the box include a charger?
Not in our library. None of the 41 phone pages records a charger in the box. Apple lists a USB-C charge cable, with no power adapter, for the iPhone 17, and several Samsung pages record a 25W or 45W adapter as sold separately. Plan to buy one or reuse an adapter that matches your phone’s row.
Which charging standard should the charger support?
For most wired phone charging, look for USB Power Delivery over USB-C. The USB-IF describes USB PD as letting each device take only the power it requires, and says certified USB Fast Chargers are backwards compatible with USB Type-C and USB Power Delivery devices. Samsung’s Super Fast Charging 2.0 builds on the optional PPS feature, which is why a Samsung-approved adapter matters for that phone.
How do I check that a charger is genuine and certified?
Look for certification marks, buy from a trusted seller, and distrust anything unbranded. The USB-IF reminds consumers to buy compliant USB products from trusted sources that display USB-IF certified logos on packaging, in product briefs or on the product itself. Marks can be copied, so pair them with a seller you trust.
| Check | Why it matters | Source |
|---|---|---|
| USB-IF certified logo on the product or box | Meant to show the product was tested against the standard | USB-IF |
| A seller you trust | UL warned in November 2020 that two USB charger models carried counterfeit UL marks and had never been evaluated for fire, shock or injury risk | UL |
| Brand, model number and markings present | Electrical Safety First tested 50 counterfeit or lookalike iPhone chargers in 2017; 49 failed basic safety checks and 68% carried a severe risk of electric shock | Electrical Safety First |
| Maker guidance followed | Samsung says to use only Samsung-approved charging devices, and that other accessories may invalidate your warranty and cause damage | Samsung |
That charity study covered one kind of lookalike charger in one country, but its advice to buy directly from trusted retailers applies broadly. The charger safety guide and cable buying safety go deeper.
Can I use a third-party charger with an iPhone?
Often yes, but follow Apple’s guidance for your model. Apple says you might not be able to charge an iOS device using USB-C power adapters that are not made by Apple. Its MagSafe page, in contrast, recommends a 30W or greater Apple USB-C power adapter or a compatible third-party USB-C adapter. The two statements apply to different products, so read the Apple page for the accessory you are buying.
Does a GaN charger charge faster?
No, not by itself. GaN chargers use gallium nitride, a chip material that can reduce size and waste heat. Texas Instruments, a chip maker, says its GaN devices can reduce consumer AC/DC solution sizes by as much as 50%, which is a maker claim rather than a test of any charger. The rated wattage and supported standard decide speed, so compare those on the label.
Does the outlet or the cable change anything?
Yes, both can. Samsung says to connect the adapter to a power outlet for the fastest charging, because plugging the USB cable into a computer or another device lengthens the time. The cable has its own rating: see cable buying safety for the table of cable ratings, and USB-C explained.
What is a simple buying checklist?
This checklist is ours, built from the sources above.
- Find your phone’s published figure in the wattage guide or on its phone page.
- Choose an adapter at or above that wattage that supports the same standard.
- Check for certification and buy from a seller you trust, not an unbranded listing.
- Pair it with a cable rated for the power.
- Use a wall outlet when speed matters.
Related
Accessories hub, wireless chargers, power banks, chargers hub, charger safety guide, USB Power Delivery.