Quick answer: Four different products are sold as an HDMI to USB connector. A capture device turns HDMI video into a USB camera stream. A power tap uses the 5 V pin on the HDMI port to run a small accessory. A USB to HDMI adapter runs the other way and needs DisplayLink or Alt Mode. A passive HDMI to USB cable cannot work, because the two interfaces share no signalling.
The phrase is ambiguous enough that buyers regularly order the wrong direction. Sorting the four cases before you shop removes almost every return in this category.
The four things people mean
HDMI in, USB out: capture
This is the only common HDMI to USB product. The box receives HDMI, decodes it, and presents a UVC video device plus a UAC audio device over USB. No driver is needed on Windows, macOS or Linux, and it works with OBS, Teams and Zoom.
HDMI power tap
HDMI sources must supply 5 V at 50 mA on pin 18. Small adapters use that to power an LED or a splitter. It is enough for a few milliamps, not for charging a phone or running a drive.
USB to HDMI: the reverse direction
Adapters sold to connect a laptop to a TV run USB to HDMI, not HDMI to USB. They need DisplayLink compression or USB-C Alt Mode, and they are covered on the USB-C pages rather than here.
Passive cable: does not exist
A cable with an HDMI plug on one end and a USB-A plug on the other cannot carry video into a computer. USB-A ports do not accept a video stream, and HDMI does not enumerate as a USB device.
Capture card limits worth knowing
Most inexpensive units are USB 2.0 with MJPEG compression, which caps at 1080p 30 Hz and adds 100 to 150 ms of latency. USB 3.0 models with uncompressed YUY2 reach 1080p 60 Hz and about 60 ms. For a webcam feed that is fine; for gaming it is not. Read the listing carefully, because many quote 4K input and 1080p output in the same sentence, and the 4K figure only describes the loop-through port.
UVC and UAC, no drivers
The device announces itself as a camera and, if it has an HDMI audio embedder, as a microphone. That is why it works everywhere. The trade-off is that advanced features such as colour space control sit in the capture software, not in the device.
HDCP will block you
Protected content from a streaming box or a game console handshake will not pass through a cheap capture card. The screen goes black and the software reports no signal. Use the console’s own capture feature or a splitter that strips HDCP only where local law allows it.
Direction and device at a glance
| Product | Direction | Bandwidth | Driver | Typical use |
|---|
| USB 2.0 capture | HDMI to USB | 1080p 30, MJPEG | UVC | Calls, lectures |
| USB 3.0 capture | HDMI to USB | 1080p 60, YUY2 | UVC | Streaming, recording |
| Power tap | HDMI to 5 V | 50 mA | None | LED, small splitter |
| USB to HDMI adapter | USB to HDMI | 1080p to 4K 30 | DisplayLink | Second screen |
| Passive cable | None | Zero | None | Nothing |
Practical scenarios
- Camera into a laptop for streaming: HDMI out of the camera into a USB 3.0 capture stick, OBS set to 1080p 60, audio taken from the same device.
- Old camcorder digitisation: a capture device with analog input plus an HDMI loop, recording to disk while the tape plays once.
- Conference room PC: a USB 3.0 capture box on the room PC so a guest laptop can share over HDMI without installing software.
- Raspberry Pi project: a USB 2.0 capture stick is enough for a 720p monitor feed and draws well under the port limit.
FAQ
Can I connect my TV to a laptop with an HDMI to USB cable?
Only through a capture device. A cable will not work because the laptop’s USB port cannot receive an HDMI stream. The capture box appears as a camera and you record or preview that feed.
Does the adapter work in both directions?
No. Capture devices are one way, HDMI in and USB out. USB to HDMI adapters are separate products with their own chips and drivers.
Why is there no picture from my console?
HDCP. Consoles protect their output, and most capture devices refuse the handshake. Use the console’s built-in recording or a compliant capture device designed for game consoles.
Next step
Decide the direction first, then check whether the host port is USB 2.0 or 3.0, because that decides 30 or 60 frames per second. The HDMI to USB 3.0 adapter page covers the capture path in detail, the HDMI to USB-C adapter page covers the USB-C variants, and USB-A vs USB-C explains why the port type changes what the same chip can deliver.
