// Overlay · Cortisol meter
The cortisol meter overlay for streamers.
A live stress gauge for your stream: a swinging needle on a six-zone dial, driven by your real heart-rate variability, not a fake animation. Idle when you're calm, pinned when you're not.
// How it works
Real stress, on a dial.
- 01
Reads your HRV
Nerva computes a stress score from heart-rate variability, RMSSD, SDNN, pNN50 and a Baevsky-style index.
- 02
Drives the needle
The 0 to 100 score swings the needle across a green to amber to red dial, locally and in real time. No cloud lag.
- 03
Yours to restyle
It's open HTML/CSS/JS. Recolor it, reposition it, or use the clear variant with no card frame.
Cortisol meter
The framed card version with the half-dial, label and BPM readout.
Cortisol meter (clear)
Dial and readout on transparent, no card frame, drops cleanly over gameplay.
A gag gauge, on a real signal
No heart-rate sensor can read blood cortisol, and the Cortisol Meter doesn't pretend to. What it does is honest in its own way: it reads your live heart-rate variability, the tiny variation in timing between beats that tracks how your nervous system is coping, and turns that into a single stress number on screen. The cortisol framing is the joke; the signal underneath is the same stress index serious users put on stream.
When the meter reads low vs high
- Low cortisol meter. HRV is high, you're relaxed and in control. The gauge sits near the bottom and your chat can see you're unbothered.
- High cortisol meter. A clutch round, a jump scare, a raid gone wrong: HRV drops, the stress index spikes, and the meter climbs in real time for everyone to watch.
- Live, all session. It tracks continuously, so the rise and fall is part of the show rather than a static badge.
- All local. HRV and the stress index are computed on your machine. Nothing about your heart rate touches a server, and there's no added latency.
Make it yours
The Cortisol Meter is an open HTML/CSS/JS overlay folder that reads the live stress value as a CSS variable, so you can recolor the gauge, swap the dial, animate it harder as the number climbs, or build a completely different meter on the same signal. For the most accurate reading, use a chest strap like the Polar H10.
Want the serious version of this signal? See the HRV stress overlay. Setting it up in OBS? Follow the heart-rate overlay for OBS guide. Browse every theme on the overlays page, or compare tools in Nerva vs Pulsoid vs HypeRate.
// FAQ
The cortisol meter, answered.
Is the cortisol meter measuring real cortisol?
Not blood cortisol, no overlay can do that from a heart-rate sensor. The Cortisol Meter is a stream gauge driven by a real heart-rate-variability stress score: Nerva reads beat-to-beat timing from your BLE sensor, computes HRV (RMSSD, SDNN, pNN50), and derives a stress index. The meter rises and falls with that index, so it reflects your actual nervous-system arousal under pressure, framed as a playful cortisol gauge.
What makes the meter read low or high?
The meter tracks your live stress score. When your HRV is high and you're calm, it reads low. When you tense up under a clutch moment and HRV drops, the stress index climbs and the meter reads high. It moves in real time as your session goes on.
What sensor do I need for the cortisol meter?
A chest strap such as the Polar H10 gives the most accurate reading, because the stress score needs precise beat-to-beat HRV timing. A watch (Garmin, Polar, COROS, Amazfit, Wear OS) gives a usable trend, but a chest strap is the gold standard.
Can I restyle the cortisol meter?
Yes. The Cortisol Meter is an open HTML/CSS/JS overlay folder that reads the live stress value as a CSS variable, so you can recolor it, change the gauge, animate it, or build your own meter from scratch. Restyle the bundled one or commission a bespoke version.
Does the cortisol meter add latency or send my data anywhere?
No. HRV, the stress index, and the overlay are all computed and rendered on your machine, with no cloud in the path. Nothing about your heart rate leaves your computer, and the meter updates with no perceptible lag.
How do I add the cortisol meter to OBS?
Add it as a Browser Source pointing at the overlay, the same as any Nerva overlay. The heart-rate overlay for OBS guide walks through the setup step by step.