Not EEG — fNIRS prefrontal training in a simple game-based form. Easy to use, narrowly focused.
Best for users seeking the simplest neurofeedback experience focused purely on prefrontal attention training.
Mendi is a Swedish-built headband that measures prefrontal cortex blood-oxygenation via fNIRS (functional near-infrared spectroscopy) rather than EEG, and feeds the signal into a game-based neurofeedback experience: keep the ball flying by sustaining attention to your forehead activity. Included here because it is in the consumer brain-training buying conversation even though the modality is different. Simpler than EEG, easier to learn, narrower in scope.
How we tested: Evidence-based assessment — scored from Mendi product documentation, the published fNIRS neurofeedback literature and independent 2026 reviews. Not hands-on tested by ONDA.
fNIRS optodes over the prefrontal cortex — measures blood-oxygenation changes rather than electrical activity. Single-region measurement, simpler than EEG but less informationally rich.
Training programmes and content
7.5
Game-based neurofeedback: a ball rises with sustained prefrontal activity. Simple programme, no meditation library, no sleep — pure focus training.
Insights and analysis quality
7.0
Per-session focus scores plus aggregate trend data. Less analytical depth than EEG-based devices.
Comfort and wearability
8.0
Simple forehead band — comfortable for 10–15 minute sessions, easy to put on and remove.
App and integration UX
7.5
Polished iOS/Android app with clean game-driven session flow.
Open data and developer access
5.0
Closed system — no raw data export or SDK. Not a developer platform.
Value
7.5
$299 hardware, no subscription required. Cheaper than Muse S Athena, more expensive than Muse 2.
Pros
+Game-based neurofeedback — easiest learning curve in the category
+Single forehead band — most comfortable form factor for focus sessions
+No subscription required
+fNIRS gives a different signal modality from EEG — useful if EEG has not worked for you
Cons
−Not EEG — fNIRS is a different (and narrower) signal
−Single-region measurement only (prefrontal cortex)
−No meditation library or sleep tracking
−Closed data platform — no developer access
Price: $299 one-time; no subscription (as of 2026-05-21)
Where it leads
Mendi is the gentlest entry into neurofeedback. The fNIRS sensor on the forehead measures blood-oxygenation changes in the prefrontal cortex — a different signal from EEG, simpler to interpret — and feeds it into a single game: a ball rises as you sustain prefrontal activity, falls as you lose focus. There is nothing else to learn. Sessions are short, the app is clean, and the device is the most comfortable in this list.
Where it falls short
Mendi is also the narrowest entry. fNIRS is not EEG — different modality, different interpretation, single-region measurement only — and the platform offers no meditation library, no sleep tracking, no developer access. For users who want anything beyond pure prefrontal attention training, Mendi is the wrong shape.
Who it is for
Choose Mendi if the simplest possible neurofeedback experience is exactly what you want, or if EEG-based devices have not produced a clear signal for you and a different modality is worth trying. For meditation breadth, Muse S Athena or Muse 2. For real EEG with developer access, Neurosity Crown or Emotiv Insight 2.
Background reading
The neuroscience these headsets feed back — and the cognitive states the EEG signal reveals.