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
Mendi’s own per-session score 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
$379 list (frequently on sale), 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 — may suit some users who did not get on with EEG
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: $379 one-time list price, often discounted (about $284 in a Sept 2026 sale); no subscription (as of 2026-09-30)
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 the prefrontal oxygenation signal climbs and falls as it drops. There is nothing else to learn. Sessions are short, the app is clean, and the device is the most comfortable in this list.
What are the downsides of Mendi?
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 should buy Mendi?
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 behind Mendi’s signal — fNIRS measures blood oxygenation in the prefrontal cortex, not electrical brain activity — and what feedback training can and cannot do.
Mendi is worth it if you want the simplest neurofeedback experience focused on prefrontal attention training. Its game-based format has the easiest learning curve in the category, it uses a comfortable single forehead band, and there is no subscription. It does not include a meditation library or sleep tracking.
How much does Mendi cost?
Mendi has a $379 list price (often discounted, about $284 in a September 2026 sale) as a one-time purchase, with no subscription required. That covers the single forehead band and its game-based neurofeedback training, though it does not include a meditation library or sleep tracking.
What are the downsides of Mendi?
Mendi is not EEG: it uses fNIRS, a different and narrower signal, and it measures only one region, the prefrontal cortex. It has no meditation library or sleep tracking, and its data platform is closed, with no developer access.
Who is Mendi best for?
Mendi is best for users seeking the simplest neurofeedback experience focused purely on prefrontal attention training. Because fNIRS measures a different signal, it may suit some people who did not get on with EEG headsets, though no study compares the two for this.
