Why is my phone charging so slowly all of a sudden?

Look at what changed. A new or different cable, a different wall plug, a hot room or a new case can all slow it down. So can lint packed into the port. Try your old charger, clean the port gently and let the phone cool. If it was fine yesterday on the same charger, the cable or the port is the usual cause.

Why is my iPhone charging slowly after 80 percent?

That is usually on purpose. Apple says Optimized Battery Charging can hold the charge at 80 percent when it expects a long charge, like overnight. On iPhone 15 and later, a Charge Limit can also stop it short of 100. Apple also says software may limit charging above 80 percent if the battery gets too warm.

What charger do I need to fast charge my phone?

It depends on the phone. Apple says an iPhone 17 needs a 40 watt or larger USB-C adapter for its fastest speed, and an iPhone Air needs 20 watts or more. Google says a Pixel 11 needs a 30 watt USB-C PPS charger and a Pixel 11 Pro XL needs 45 watts. Samsung says a regular charger will not fast charge a Galaxy.

Does Airplane Mode charge your phone faster?

It can help a little, because the phone stops using its radios. The bigger win is putting the phone down. Samsung says browsing, video and games while charging slow the charge to keep the phone from overheating, and apps that use the network can drain power while it charges.

Why is my phone charging slowly on a wireless charger?

Wireless is slower than a cable, and small things slow it more. Samsung says a case, or anything between the phone and the pad, can slow it or cause heat. Apple says the fastest MagSafe speeds need a 30 watt or larger USB-C adapter behind the charger.

Is slow charging bad for my battery?

No. Apple says how fast a battery ages depends on things like its temperature history and how it is charged. Heat is the thing to avoid. A slow, cool charge overnight is fine.

Why Is My Phone Charging So Slowly? How to Find the Bottleneck and Fix It

Your phone is charging slowly because one part of the chain cannot keep up. That is the wall adapter, the cable, the port, the phone's temperature or a battery setting that slows things down on purpose. The phone only charges as fast as the weakest of those.

So do not buy a new charger yet. Find the weak link first. It takes about five minutes, and half the time the fix is free.

The Short Answer

Check the adapter. It needs enough watts for your phone. The number is printed on the plug.
Swap the cable. Cables wear out inside long before they look broken.
Clean the port. Lint packs into it from your pocket.
Let it cool. A hot phone slows its own charging to protect the battery.
Check the battery settings. A charge limit or 80 percent hold is not a fault.
Plug into the wall. Laptop, car and hub ports are slow by design.

How Fast Is Normal?

You cannot tell if your phone is slow until you know what it is supposed to do. Here is what the makers say, with the charger each one needs.

iPhone

From Apple's fast charging page:

iPhone 18 Pro and 18 Pro Max. Up to 50 percent in about 15 minutes, with Apple's 40 watt Dynamic Power Adapter or a 60 watt or larger adapter that supports USB Power Delivery 3.2 with AVS.
iPhone 17, 17 Pro and 17 Pro Max. Up to 50 percent in about 20 minutes, with a 40 watt or larger adapter.
iPhone 17e and iPhone Air. Up to 50 percent in about 30 minutes, with a 20 watt or larger adapter.
Older iPhones. Apple says to use an 18 watt or larger USB-C adapter for fast charging.
MagSafe. Apple says iPhone 16, 17 and Air need a 30 watt or larger adapter behind the MagSafe Charger for fast wireless charging. iPhone 15 and earlier top out at 15 watts.

Apple measured these on drained phones, so the last stretch to 100 always takes longer.

Pixel

From Google's Pixel tech specs:

Pixel 11 Pro XL. About 75 percent in 30 minutes with a 45 watt USB-C PPS charger.
Pixel 11 and Pixel 11 Pro. About 55 percent in 30 minutes with a 30 watt USB-C PPS charger.
Pixel 10a. About 50 percent in 30 minutes with a 45 watt USB-C PPS charger.

Google says those numbers come from its own 45 watt charger plugged into a wall. PPS is a charging standard. A charger without it can still charge a Pixel, just slower.

Galaxy

Samsung says you cannot fast charge with a regular charger. The phone, the charger and the cable all have to support fast charging. Samsung also has switches for it, which we cover below.

A Worked Example

Say you have an iPhone 17 and the old 5 watt cube from a drawer. Apple's 50 percent in 20 minutes needs 40 watts. Your cube gives one eighth of that. Your phone is not broken. It is starving.

The Five Minute Test

Change one thing at a time. If you swap the cable and the charger together, you will not know which one was bad.

Step 1. Use the Wall

Plug into a wall outlet, not a laptop, a car or a power strip with USB ports. Belkin says a laptop or hub port gives roughly 2.5 to 4.5 watts. Samsung says a computer port slows charging too. Google suggests plugging a lamp into the outlet to make sure it works.

Step 2. Check the Adapter

Read the watts on the plug. Apple says the number is printed on the top or bottom. Compare it with the list above. If it is lower than your phone needs, that is your answer.

Watch out for chargers with more than one port. Belkin says they can split their power when two things are plugged in. Unplug the other device and test again.

Step 3. Swap the Cable

Try a different cable you know is good. Google says to try another cable when charging is slow, and to test your cable and adapter on another device. Apple says to stop using any cable or adapter that is bent, frayed or broken.

Cables matter more than people think. Belkin says an old USB-A cable caps an iPhone 15 or newer at 7.5 watts, and that a plain USB-C cable tops out at about 60 watts. Belkin adds that some fast Galaxy phones need a cable rated for 5 amps to hit full speed.

Step 4. Clean the Port

Look into the charging port with a light. Pocket lint gets packed into the bottom and stops the plug from seating all the way. Apple and Google both say to clear debris from the port. Samsung says to use a soft brush. Go gently. Do not use metal, and do not blow into it.

If a Galaxy shows a water drop icon, Samsung says there is moisture in the port or cable and charging will stop until it dries.

Step 5. Let It Cool and Put It Down

Heat is the quiet cause. Apple says an iPhone slows or stops charging when it gets hotter than its normal range, and it may show Charging On Hold until it cools. Apple's normal range is 32 to 95 degrees Fahrenheit. Samsung says games, video and browsing while charging slow it down to prevent overheating.

Take the case off, move the phone out of the sun and stop using it for a bit. If your phone runs hot a lot, read our guide on why your phone is so hot.

Settings That Slow Charging on Purpose

Sometimes slow charging is the phone doing its job.

iPhone

Optimized Battery Charging. Apple says the iPhone learns your routine and can hold at 80 percent until you need it, like overnight. You will see a Lock Screen note with the finish time. Touch and hold it and tap Charge Now to fill up right away.
Charge Limit. On iPhone 15 and later, you can set a limit from 80 to 100 percent. Apple says the phone stops near that limit. Find it under Settings, then Battery, then Charging.
Heat. Apple says software may limit charging above 80 percent when the battery is too warm.

On iPhone 14 and older, the setting lives under Settings, then Battery, then Battery Health and Charging. Apple warns that turning Optimized Battery Charging off can wear the battery faster. We leave it on.

Galaxy

Samsung says to open Settings, then Battery and device care, then Battery, then More battery settings. Under Charging, check that Fast charging, Super fast charging and Fast wireless charging are on. Names can vary a little by model.

Pixel

Google says a Check charging accessory alert means the cable or adapter may be damaged or not supported. Google recommends a PPS adapter of 30 watts or more, and says other USB Power Delivery adapters should be at least 15 watts.

Wireless Charging Is Slower by Design

A cable beats a pad. Google says a wired charger gives the best charging performance. Wireless also loses speed to small things.

The case. Samsung says a case can trap heat on a wireless pad. Take it off and try again.
Things in the way. Samsung says any object between the phone and the pad can slow charging, and metal or magnets can make it overheat.
The adapter behind the pad. A fast pad on a weak plug is a slow pad.
Car pads. Google says some in car wireless chargers charge on and off. A cable is steadier.

When It Is the Battery or the Port

If you tried a known good wall adapter, a known good cable, a clean port and a cool phone, and it is still slow, the problem is inside the phone. It is either a worn battery or a damaged charging port.

Check battery health. Our guide on why your phone is dying so fast shows where to find it on iPhone, Pixel and Galaxy. Below 80 percent means the battery is worn.
Wiggle test. If charging starts and stops when you move the plug, the port is loose or damaged.
Restart it. Apple lists a restart as one of its first steps. It costs nothing to try.

A worn battery or a bad port is a repair job, not a settings fix. If your phone will not charge at all, start with our guide on why your phone is not charging.

What Most Guides Get Wrong

Most pages that rank for this question are written by companies that sell chargers. Their advice is often right, but it all points to the same fix. Buy a new charger.

That is the last step, not the first. A new charger will not help if your cable is the weak link, your port is full of lint or your phone is hot. And it will not help at all if the phone is holding at 80 percent on purpose. Test first. Then, if your adapter really is too small, buy one that matches your phone's number from the list above.

The other bad tip is to turn off every battery protection setting to charge faster. Those settings exist to make the battery last longer. Leave them on and tap Charge Now on the days you need a full charge fast.

The Bottom Line

Your phone charges as fast as its weakest link. Plug into a wall. Check the watts on the adapter against your phone. Swap the cable. Clean the port. Let the phone cool. Check whether a charge limit is doing its job. If all of that is fine and it is still slow, the battery or port needs a repair.

Keep Reading

Phone makers change charging speeds every year. Follow the latest in our devices news, or browse more plain tech advice.

From the Inbox

Why is my phone charging so slowly all of a sudden?: Look at what changed. A new or different cable, a different wall plug, a hot room or a new case can all slow it down. So can lint packed into the port. Try your old charger, clean the port gently and let the phone cool. If it was fine yesterday on the same charger, the cable or the port is the usual cause.
Why is my iPhone charging slowly after 80 percent?: That is usually on purpose. Apple says Optimized Battery Charging can hold the charge at 80 percent when it expects a long charge, like overnight. On iPhone 15 and later, a Charge Limit can also stop it short of 100. Apple also says software may limit charging above 80 percent if the battery gets too warm.
What charger do I need to fast charge my phone?: It depends on the phone. Apple says an iPhone 17 needs a 40 watt or larger USB-C adapter for its fastest speed, and an iPhone Air needs 20 watts or more. Google says a Pixel 11 needs a 30 watt USB-C PPS charger and a Pixel 11 Pro XL needs 45 watts. Samsung says a regular charger will not fast charge a Galaxy.
Does Airplane Mode charge your phone faster?: It can help a little, because the phone stops using its radios. The bigger win is putting the phone down. Samsung says browsing, video and games while charging slow the charge to keep the phone from overheating, and apps that use the network can drain power while it charges.
Why does my phone charge slowly in the car?: Car USB ports and laptop ports send much less power than a wall adapter. Belkin says a laptop or hub port gives roughly 2.5 to 4.5 watts. Samsung says a computer USB port slows charging too. Use a car adapter rated for fast charging that plugs into the power outlet.
Why is my phone charging slowly on a wireless charger?: Wireless is slower than a cable, and small things slow it more. Samsung says a case, or anything between the phone and the pad, can slow it or cause heat. Apple says the fastest MagSafe speeds need a 30 watt or larger USB-C adapter behind the charger.
Is slow charging bad for my battery?: No. Apple says how fast a battery ages depends on things like its temperature history and how it is charged. Heat is the thing to avoid. A slow, cool charge overnight is fine.

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