How ONDA scores tools
Every review on ONDA is a single, named editorial assessment — not a crowd average and not an algorithm. This page is the fixed rubric behind those scores, so you can judge the judgement.
The score
Each tool gets an overall score from 0 to 10 (one decimal). It is the weighted mean of the criteria below — never a round number picked by feel. A single reviewer assigns it, so it is published as one editorial rating, not an aggregate of many.
Scoring criteria — HRV wearables
HRV measurement accuracy
25%Agreement of measured HRV (RMSSD) with an ECG chest-strap reference, drawn from peer-reviewed validation studies and side-by-side testing.
Sensor and signal quality
15%Sensor type (optical PPG vs electrical ECG), sampling approach, and how well a clean signal holds during movement and overnight.
Sleep tracking accuracy
15%How closely sleep staging and total sleep time track polysomnography or validated references — HRV is read mostly during sleep.
Data access and export
15%Access to raw and detailed data: export, an open API, and integration with third-party tools rather than a closed app.
Wearability and battery
10%Comfort and form factor for 24/7 wear, plus battery life and how much charging interrupts continuous measurement.
App and software experience
10%Clarity of the app, quality of the guidance, and whether metrics are explained rather than reduced to one opaque score.
Value
10%Hardware price together with any mandatory subscription, weighed against what the device delivers.
Hands-on tested vs evidence-based
Every review carries one of two labels. Hands-on tested means ONDA physically wore and used the device, with the test period stated. Evidence-based assessment means the tool was scored from spec sheets and peer-reviewed validation studies, each cited in the review references. We never present an assessment as hands-on testing.
Independence
No vendor pays for placement or for a score. Product links are plain links to official sites and ONDA earns no commission from them. If that ever changes, affiliate links will be clearly labelled and disclosed on the page.
Who writes the reviews
Reviews are written by Yakiv Bilenko, founder of ONDA Life. About the author.