Online USB Port & Device Test

Test your USB ports and connected hardware peripherals online using standard WebUSB bus enumeration.

Ready when you are

Plug in a USB device and click below to test your USB host controller and port communication.

USB Subsystem: Universal Serial Bus Controller
WebUSB operates in a strict security sandbox with explicit user permission prompts.
Scanning USB Bus Polling USB host controller for attached devices...
USB Host Status
Initializing root hub...
API Interface
WebUSB 1.0
Enumerating USB root hub descriptors... 0%
USB Host Subsystem operational
WebUSB controller queried hardware bus with zero protocol errors.
97/100
Technical details & diagnostics
WebUSB API Status WebUSB 1.0 (Supported)
Connected Devices 1 Authorized Device(s)
Host Bus Controller xHCI / EHCI USB Host Controller
Packet Transmission Zero CRC Checksum Errors
WebUSB is Not Supported or Blocked

WebUSB requires a Chromium-based browser (Chrome, Edge, Brave, Opera) running on a secure origin (HTTPS or localhost).

  1. Ensure you are using Google Chrome version 61 or later.
  2. When the device selector pops up, choose your device and click "Connect".
  3. If you cancelled the permission prompt, click Try again below.
  1. Microsoft Edge natively supports WebUSB on Windows and macOS.
  2. Ensure USB permissions are allowed in edge://settings/content/usbDevices.
  3. Click Try again to re-trigger the device authorization prompt.
  1. Mozilla Firefox does not currently implement the WebUSB specification.
  2. To test your USB devices online, please use Google Chrome or Microsoft Edge.
No USB Device Selected

No authorized USB peripheral was chosen in the browser dialog, or no compatible device is currently plugged into your USB ports.

Ensure your USB cable or flash drive is firmly seated into a functional USB port.
Note that keyboards and mice are claimed by the operating system kernel and cannot be paired via WebUSB.
Preview State:
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How to Test USB Ports & Peripherals Online

1
Connect your peripheral
Plug any USB gadget, microcontroller, or peripheral into a USB port on your computer.
2
Grant browser access
Click 'Test my USB port' and select your connected peripheral in the browser prompt.
3
Verify communication
Confirm bus speed, descriptor handshakes, and stable packet transmission.

Common USB Port Problems & Fixes

Symptom Likely Cause Recommended Solution
USB device unrecognized (Code 43) Corrupt device descriptor or driver conflict in Windows Device Manager. Unplug the device, open Device Manager, uninstall the unknown USB device, and restart your computer to reinstall clean drivers.
Intermittent USB disconnections Loose connector pins, physical port debris, or power delivery sagging. Clean dust out of the port using compressed air, try a different port, and avoid unpowered passive USB splitters for high-draw devices.
SuperSpeed device running slow (USB 2.0) Plugged into a legacy USB 2.0 black port or using a charging-only cable. Connect to a blue or teal USB 3.0/3.2 port and ensure the USB cable is rated for high-speed data transfer rather than power charging only.
USB device not listed in browser selector OS kernel claims device (HID/Mass Storage) or WebUSB permission disabled. System keyboards and storage drives are locked by the OS for security. To test keyboards and mice, use Sharing.io.vn's dedicated input tools.

How Universal Serial Bus (USB) Hardware Works

The Universal Serial Bus (USB) standard has unified computer connectivity for over three decades. From original USB 1.1 running at 12 Mbps to modern USB4 Type-C delivering 40 Gbps, the protocol uses packet-based differential signaling across host controllers (xHCI/EHCI) and downstream ports.

When you insert a device, the host controller detects a change in line pull-up resistance (D+ / D- lines) and begins the enumeration sequence: resetting the bus, assigning a unique 7-bit bus address, reading the device descriptor (vendor ID and product ID), and loading matching interface drivers.

USB Standards Comparison Table

  • USB 2.0 (High-Speed): 480 Mbps transfer rate. 4-pin physical connector supplying up to 500mA (2.5W) of bus power.
  • USB 3.2 Gen 1 (SuperSpeed): 5.0 Gbps transfer rate. 9-pin connector with dedicated differential pairs supplying up to 900mA (4.5W).
  • USB 3.2 Gen 2x2 (SuperSpeed+): 20 Gbps transfer rate over dual Type-C differential channels.
  • USB4 & Thunderbolt 4: Up to 40 Gbps with PCIe tunneling, DisplayPort alt-mode, and up to 240W USB Power Delivery (USB-PD EPR).

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Frequently Asked Questions

What is WebUSB and how does it test USB hardware?
WebUSB is a secure W3C browser standard that enables authorized web applications to safely communicate directly with USB hardware devices, querying device descriptors and verifying endpoint connectivity.
Why are standard mice and keyboards not listed in the browser dialog?
For security reasons, operating systems claim exclusive ownership of HID (Human Interface Device) peripherals like system keyboards and mice. To test your keyboard or mouse, use Sharing.io.vn's dedicated Keyboard Test or Mouse Test tools.
Which web browsers support WebUSB?
WebUSB is natively supported in Google Chrome, Microsoft Edge, Opera, and Brave on Windows, macOS, Linux, and Android. It requires a secure HTTPS origin.
Can WebUSB harm my connected USB drive or flash memory?
No. The browser security sandbox strictly restricts low-level disk formatting and protected system commands. WebUSB only reads standard device descriptor headers and interface classes.
How can I tell if a physical USB port is damaged?
If devices repeatedly disconnect, trigger Windows Device Manager 'Code 43' errors, or fail to receive 5V bus power, the physical connector pins or onboard controller polyfuse may be worn or damaged.
What is the difference between USB 2.0, 3.0, and USB4?
USB 2.0 provides up to 480 Mbps transfer speed over 4 pins. USB 3.0 (blue ports) adds dedicated SuperSpeed differential pairs delivering 5 Gbps. USB4 over Type-C supports up to 40 Gbps with PCIe tunneling.