Fast charging is one of the essential features of modern smartphones. It’s a great way to power up your phone with a full battery. Hence, you won’t need to charge your iPhone overnight to ensure a fully charged phone for the next day.

But it might be slightly confusing to know whether your iPhone is in fast charging mode if you’re an iPhone user.

So, in this post, we will discuss how to tell if iPhone is fast charging.

Do All iPhones Have Fast Charging Mode?

Apple iPhones launched after 2017 fast support charging, introduced relatively later than the other smartphone brands. So, if you have an earlier iPhone model, fast charging may not be an option.

However, only iPhone 11 Pro and iPhone Pro Max have a fast charger. You might know that iPhone 12 doesn’t come with a charger.

Which iPhone Models Support Fast Charging

Among the new iPhone models, iPhone 8, iPhone 8 Plus, and iPhone X are among the first few phones that support fast charging. So, iPhone users can enjoy a higher battery life for their phones in a shorter time.

Avoid Complex Calculations to Confirm iPhone Charging Speed.

No formula shows how fast an iPhone can charge. Instead, the iPhone’s fast charging speed is limited to a specific battery percentage.

When the phone battery reaches 80%, it stops fast charging. This is hard-coded in iPhones. This information is critical because you might be tempted to buy a heavier power charger. Remember, 20W is the maximum sustainable power for iPhones, so going beyond that isn’t ideal.

What Do You Need to Fast Charge Your iPhone?

Before you can find out if your iPhone is fast charging, you will need the equipment. Here is what you need.

  • A fast, compatible charger having at least an 18Watt power output
  • USB-c lightning cable

Moreover, ensure that your charger supports USB Power Delivery (USB-PD) if you want to fast charge your iPhone.

How To Know if iPhone is Charging Fast

First, set up your iPhone with the power adapter to know if your iPhone is charging fast. Next, follow one of these ways to see if it’s charging fast.

Check the Lightning Bolt Indicator

Once connected, check the iPhone battery icon at the top right corner of your iPhone screen. If you see a lightning bolt indicator next to the battery percentage indicator, your iPhone is fast charging.

Check the Settings App

If your iPhone model supports fast charging but doesn’t charge as fast, you must confirm if the fast charging feature is turned on.

Go to the Settings app and navigate to the Fast Charging option. If it’s turned off, switch it ON and check if your iPhone is fast charging after that.

Check the Battery Percentage Indicator

The third option is to monitor the iPhone’s battery percentage. If your iPhone is fast charging, the battery life is jumping up quicker than usual. Usually, your phone should reach a full charge in about an hour and a half.

Check Your Lightning Cable if your iPhone isn’t Fast Charging.

At times, the fast-charging cable can malfunction. Hence, even with all the basics, it won’t fast charge your iPhone. In such cases, make sure that your cable is connected correctly.

Technical Standards for Fast Charging

While learning about iPhone fast charging, knowing the minimum electrical requirements to ensure fast charging is also helpful. Hence, you will realize that not all devices can fast charge.

Minimum Power Requirements

Your power adapter should be at least 18 Watts for fast charging. Some of the latest iPhones, like the iPhone 11, also support up to 30 watts of fast chargers.

Can You Use a 12w charger for iPhone Fast Charging?

It’s pretty much impossible to fast charge with a 12W adapter. Moreover, the adapter type and iPhone model also play a critical role in whether it charges fast or not.

Minimum Current Requirement for Fast Charging

Ensure your C to lightning cable can support at least 2.4A of charging current. This is the minimum current required for fast charging. Most iPhones and iPads use this standard for fast-charging applications.


A large-capacity charger can ensure fast charging standards and provide stable voltages at higher current ratings. In addition, if your phone is compatible with fast charging, it can reduce the charging time dramatically.