Can I charge my phone with a laptop USB port?
How it works and what to expect
A standard USB-A port on a laptop usually provides 0.5A at 5V (2.5W), which charges a phone very slowly—often just enough to maintain battery if you're using it. USB 3.0 ports can supply up to 0.9A (4.5W), and some laptops have charging ports that deliver more.
Newer laptops with USB-C may support USB Power Delivery (USB PD), which can charge phones at higher speeds, up to 15W or more. Check your laptop's specs. If it supports USB PD, you can charge quickly with a USB-C to Lightning or USB-C cable.
- USB-A: typically 0.5A–0.9A, slow charging
- USB-C with USB PD: up to 15W or more, faster
- Charging while using the phone may drain battery
- Some laptops have dedicated charging ports with higher output
When to use a laptop port
Use a laptop port when you don't have a wall charger handy, or for overnight charging when speed doesn't matter. It's also fine for topping off. But for fast charging, use a dedicated wall charger that matches your phone's fast-charging standard.
Keep in mind that charging a phone from a laptop can drain the laptop's battery faster if it's unplugged. If the laptop is plugged in, it's usually fine.
Common mistakes
- Expecting fast charging from a standard USB-A port.
- Assuming all USB-C ports on laptops support USB PD.
- Using a laptop port that doesn't provide enough power, causing the phone to lose charge while in use.
