// Nerva vs Pulsoid
The best Pulsoid alternative for streamers who hate lag.
Pulsoid is the most popular heart-rate overlay, with a huge widget and integration library. The catch is architecture: it routes your heart rate through the cloud. Nerva connects to your sensor directly on the desktop, so the number moves the instant your heart does, and the overlay is code you own. Here's the honest split.
Choose Nerva if
- you want zero cloud lag between a beat and the overlay
- you want to fully customize the overlay as HTML/CSS/JS, or commission one
- you want a real HRV stress score, not just BPM
- you'd rather not bridge through a phone
Stick with Pulsoid if
- you rely on its large widget and integration ecosystem (Discord, Stream Deck, Voicemod)
- you want a free tier and don't mind a cloud-routed setup
- you specifically need Apple Watch
Side by side
| Nerva | Pulsoid | |
|---|---|---|
| Latency | None you can perceive. Direct BLE connection; your heart beats, the overlay moves. | Cloud round-trip adds a noticeable lag between the beat and the screen. |
| How it connects | Strap/watch → app → overlay, all on your machine. One hop, no server in the middle. | Sensor → phone app → Pulsoid cloud → browser-source widget. |
| Phone required | No. The desktop app pairs with the sensor over BLE directly. | Yes, typically. The phone app bridges the sensor to the cloud. |
| Customization | Fully customizable. Overlays are open HTML/CSS/JS; edit them or write your own from scratch. | Configure preset widgets (colors, fonts, ranges). No code-level control. |
| Stress, not just BPM | Derived stress score from HRV (RMSSD, SDNN, pNN50, Baevsky index). | Raw BPM and zones. No derived HRV stress index. |
| Sensor compatibility | Any BLE Heart Rate device (UUID 0x180D): Garmin, Polar, COROS, Amazfit, Wear OS. | Wide sensor support, plus Apple Watch and phone sensors through the app. |
| Apple Watch | Not supported; it doesn't broadcast BLE heart rate. | Supported through the phone app. |
| Ecosystem | Focused: the app, the overlays, and bespoke overlay commissions. | Large widget and integration library (Discord, Stream Deck, Voicemod). |
| Price | 1-month free trial (no card), then €90/yr or €10/mo. Funds active upkeep by one dev. | Free tier; paid plans unlock advanced widgets and integrations. |
Last reviewed June 2026 against Pulsoid's own site. Corrections: [email protected].
The latency difference, concretely
Pulsoid's path is sensor → phone app → Pulsoid cloud → browser-source widget. Every hop adds delay, and the cloud round-trip is the one you feel on a tense moment, the spike lands on screen a beat late. Nerva's path is sensor → desktop app → overlay, all on your machine. There's no server in the middle, so the overlay reacts as fast as the BLE link itself.
Customization: widgets vs. code
Pulsoid gives you a library of preset widgets you configure, colors, fonts, ranges. That's fast and friendly. Nerva takes the opposite stance: overlays are open HTML/CSS/JS folders that read live values as CSS variables, so you can restyle a bundled one or build something nobody else runs. If you want a look that's genuinely yours, that's the difference.
What switching from Pulsoid involves
Your sensor carries over: any BLE strap or watch you paired with Pulsoid works with Nerva, except an Apple Watch (it doesn't broadcast BLE heart rate). You drop the Nerva overlay into OBS or Streamlabs as a local browser source, the same slot the Pulsoid widget used. The phone app Pulsoid needed to bridge the sensor is gone: Nerva pairs with the sensor directly. The overlay itself is rebuilt rather than imported, because Nerva's are editable code, not preset widgets.
Where Pulsoid wins
This isn't a hit piece. Pulsoid's ecosystem is genuinely broad, Discord, Stream Deck, Voicemod and more, it has a generous free tier, and it supports Apple Watch, which Nerva can't. If those are decisive for you, Pulsoid is the right tool and you should use it.
// FAQ
Switching from Pulsoid, answered.
Should I switch from Pulsoid to Nerva?
Switch if the lag bothers you. Pulsoid sends your heart rate to its cloud before the widget updates, so on a tense moment there's a round-trip you can feel. Nerva reads your BLE strap or watch directly on the desktop and draws the overlay locally, so the number moves the instant your heart does. You'd also switch if you want to own the overlay markup or show a real HRV-based stress score, not just BPM. Stay on Pulsoid if its widget and integration library (Discord, Stream Deck, Voicemod) or its free tier are what you rely on.
Can I keep the same heart-rate sensor I used with Pulsoid?
Almost certainly. Nerva works with any device that broadcasts the standard BLE Heart Rate Service (UUID 0x180D): chest straps like the Polar H10, and watches from Garmin, Polar, COROS, Amazfit, and Wear OS. The one exception is Apple Watch, which doesn't broadcast BLE heart rate; Pulsoid supports it through its phone app, Nerva can't.
Do I still need the phone app I used for Pulsoid?
No. Pulsoid usually relies on its phone app to bridge the sensor to its cloud. Nerva's desktop app pairs with your BLE strap or watch directly, so there's no phone in the loop at all.
Will my Pulsoid overlay setup transfer to Nerva?
The sensor pairing carries over, the overlay doesn't, because they work differently. Pulsoid gives you preset widgets you configure; Nerva gives you open HTML/CSS/JS overlays that read live values (BPM, stress, zone) as CSS variables. You drop a Nerva overlay into OBS or Streamlabs as a local browser source, the same way you added the Pulsoid widget. You can restyle a bundled overlay, build your own, or commission a bespoke one.
Does Nerva have a free tier like Pulsoid?
Not a permanent free tier, but a full 1-month free trial with no card and no account. After that it's €90/yr or €10/mo, with a 30-day refund on the annual plan. Nerva is paid because it's maintained by one developer with no cloud to monetize, no ads, and no data resale, so the subscription is what funds upkeep and new features.
Is Nerva really lower-latency than Pulsoid?
Yes, by design rather than by tuning. Pulsoid's path is sensor → phone → cloud → widget, so the overlay can only update after a server round-trip. Nerva's path is sensor → desktop app → overlay, all on your machine, so the only meaningful delay is the BLE link itself. There's no third-party broker between your strap and your stream.
See also: Nerva vs HypeRate · full comparison