Show HN: A weird thing that detects your pulse from the browser video

by kilroy123on 3/4/2026, 2:24 PMwith 54 comments

by functionmouseon 3/8/2026, 2:15 AM

I feel like the primary use case for such a technology is manipulating and profiling people over video chat, maybe even autonomously. Hiring managers, HR, landlords, and police are obvious customers.

The response I anticipate will be "But this will help doctors over telehealth and stuff!" - Please see https://calebhearth.com/dont-get-distracted

by hluskaon 3/8/2026, 2:04 AM

I would prefer some kind of privacy statement or even some kind of explanation about what is going on before I just randomly turn my webcam on. This might be great and I’m proud of you for launching but I don’t do things like that. Heck, videos can make a person’s heart race - I had my first attack at 39 and that’s a hell of a lot of risk.

by _Microfton 3/8/2026, 7:40 AM

You as reader might also be interested in this: https://hbenbel.github.io/blog/evm/

by twodaveon 3/8/2026, 2:39 AM

It’s not very accurate. Maybe because of the camera fidelity. It was about 10bpm lower than actual for me. Seems to operate off of subtle motions caused by pulse. It was even worse at detecting breathing.

by jmusallon 3/8/2026, 3:00 AM

May be related: Explanation of motion and color amplification in video by Steve Mould https://youtube.com/watch?v=rEoc0YoALt0

He even shows pulse detection (around 8:30).

by thePhytochemiston 3/8/2026, 3:27 PM

Love the attempt, but after giving it a good image and letting it run for a while it's totally off. I measure my heartbeat at 100 bpm and it's reading around 50. I see some cool looking UI stuff but the actual measurement isn't accurate.

by smusamashahon 3/8/2026, 5:24 AM

I made my own heart rate app (using gemini at first and then Claude for lots of further edits). https://xosh.org/heart-rate/ https://github.com/SMUsamaShah/heart-rate it's all offline. UI needs more work but me and my wife are the only users therefore it doesn't matter that much.

At one point I added the same EVM based heart rate detection but that requires sitting very still. I use it on my phone mainly therefore the common finger method is easiest one to use.

by abakkeron 3/8/2026, 2:53 AM

It registered in the low 40s for me, while my watch was saying 72-75. I guess YMMV

by amagasakion 3/8/2026, 1:51 AM

Could be interesting, but allowing the webcam crashes my browser.Repeatedly

macOS 15.7.1 (24G231) Brave 1.87.186 (Official Build) (arm64) Chromium: 145.0.7632.45

by sxpon 3/8/2026, 3:57 AM

How does it work? Is it https://people.csail.mit.edu/mrub/evm/? I see the FAQ about VitalLens, but I couldn't find technical details.

It's super cool. Thanks for sharing. I want to build a biofeedback app for meditation and this looks like a good platform to use.

by trothamelon 3/8/2026, 3:47 AM

There's a version of this built into the Google Fit application for Android.

by gumboshoeson 3/8/2026, 1:55 AM

Worked for me on Android. Love the simplicity.