20W or 30W Chargers - How to choose?

In terms of watts, higher is generally better!

20W or 30W Chargers - How to choose?
Page content

In today’s digital world, every individual has technology devices like smartphones and laptops that are essential in their daily routine. These technology devices need to be charged frequently, and the type of charger one uses determines their charging speed. With more and more advanced smartphones on the market, manufacturers have been introducing different types of chargers, each time a bit more powerful. As you can guess, there are chargers with very different power capacities out there, for example, your iPhone or iPad charger from a few years ago is probably less powerful than the ones that come with this year’s devices. The two most common wattages we can find on our charger laying around those days are 20W or 30W, and people keep asking me about the difference between those two wattages, which I will explain in detail in this article.

Difference between a 30W and a 20W charger

A 30W charger is basically a charger that can transmit power to your device (phone, tablet, etc.) faster than a 20W charger. A device with a higher wattage can transfer energy to the battery of a technology device faster than that of a lower-wattage charger, it’s as simple as that. On the other hand, a 20W charger has a lower wattage rate than a 30W charger, so it will charge your device slower. Keep in mind that even if a 20W charger charges a device at a lesser rate than a 30W, it is still relatively faster than a 5W charger that is generally sold with previous iPhones.

30W vs 20W for charging speed

Without any doubt, a 30W charger is faster than a 20W charger. When you use a 30W charger, your device will replenish its battery life more quickly than when you use a 20W charger. For instance, an iPad that takes about 5 hours to charge when using a 20W charger will only take about 2 hours when charged with a 30W charger. The difference in charging speed is highly significant, especially for devices that support quick charging and high-speed charging sessions (more on that below).

Tips to memorize: the higher the watts (W) value is, the faster the charger will charge your device, as long as your device can leverage this additional power.

30W vs 20W chargers: which one is generally better?

Whether a 30W charger is better than a 20W charger depends on the intended use, but ultimately there is no advantage to having a lower-wattage charger. Typically, there is no harm in using a 30W charger to charge your device, but one may argue that it is not essential, especially when you have a 20W or a 18W charger. However, a 30W charger may be preferable for individuals who place high demands on their technology devices during their daily routine. If you plan to buy a new charger, you can’t go wrong going with the higher wattage value, it will be more future-proof.

20W or 30W charger for an iPhone?

It is safe to use both a 20W and a 30W charger for charging an iPhone (I even do plug my iPhone to my 65W laptop adapter via a USB-C to lightning cable without any issue). However, it is essential to note that the early iPhones doesn’t support 30W charging so a faster charger won’t charge it faster. The fast charging feature is available from the iPhone 8 and later models and requires the use of an 18W, 20W, 29W, 30W, 61W, or 87W USB-C Power Adapter (but any value in-between is fine as well).

Using a 30W Charger for your iPhone

iPhones only require a 5W charger, but you can use higher-rated chargers to boost the charging speed of your iPhone. A 30W charger can’t damage your iPhone’s battery in the long run as the device is only “taking” from the charger what it can support.

We can see Apple selling a 30 watts charger here https://www.apple.com/shop/product/MY1W2AM/A/30w-usb-c-power-adapter, and mentioning it can be used on iPhone and iPad.

Safety of using a 30W charger with an iPhone

It is safe to charge an iPhone with a 30W charger. All Apple devices with a lightning port can be charged with any 5V power supply. An iPhone is designed to utilize at least a 5W charger rated at 5V, 1A, but it can accept more, and later models utilize fast charging technology that requires an 18W or higher-rated charger.


When it comes to selecting a charger for your technology device, whether it is a 30W or 20W charger, it is, in fact, not essential to use the right-rated power. Although a 30W charger can charge devices more quickly, a 20W will work fine, and a 60W will charge even more quickly if the device supports it.

Photo by Solen Feyissa on Unsplash