Compare
Underlay.fm vs Brain.fm
Brain.fm is AI-generated functional music, engineered around real neural phase locking research. Underlay.fm uses no music at all, synthesizing a fresh soundscape around your task and mood every time you press start.
Brain.fm is still music
Brain.fm's neural phase locking research is real, and the company holds patents on the approach. But what you hear is still AI-generated music: melody, rhythm, and harmonic structure engineered to a purpose. Your auditory cortex processes that structure automatically, whether or not you're paying conscious attention to it. For some listeners that's fine. For anyone who finds even "focus music" pulls at their attention, it's the same underlying problem as any other song.
It's also a fixed catalog. You pick a mode (Focus, Sleep, Relax, Meditation) and a style within it, and it plays a pre-composed track. There's no prompt asking what you're working on and no mood check-in, and over time the tracks become familiar enough that some listeners find the effect fades.
What Underlay.fm does differently
Underlay.fm doesn't use music at all. No melody, no rhythm, no chord changes, nothing built to be engaging the way a song is. Just layered tonal texture your ears can rest on without anything to follow. It also asks two questions before a session starts: what you're working on and how you're feeling. From those inputs it synthesizes the soundscape in real time. Nothing is pulled from a library, and nothing repeats in a recognizable way from session to session.
Mid-session, you can adjust warmth, depth, and individual layers without navigating away or breaking your concentration. The audio is built around your actual state that day, not a mode you selected once and reuse indefinitely.
| Underlay.fm | Brain.fm | |
|---|---|---|
| Audio type | Tonal texture, no music | AI-generated music |
| Has melody or rhythm | No | Yes |
| Built in real time or pre-composed | Real time | Pre-composed library |
| Task-aware | Yes | Mode categories only |
| Mood-aware per session | Yes | No |
| Adjustable mid-session | Warmth, depth, layers | No |
| Free trial | One session, no account | Requires account first |
| Monthly price | $7.99 | $14.99 |
| Annual price | $47.99 | $99.99 |
| Lifetime option | $79.99 one-time | Not available |
Common questions
What is Brain.fm?+
Brain.fm is AI-generated functional music built around neural phase locking, the idea that audio engineered at specific frequencies can help synchronize brain activity toward a more focused state. The company holds patents on the approach and has published research behind it. It still has musical structure though: you pick a mode (Focus, Relax, Sleep, Meditation) and a style within it, then play a pre-composed track from their library.
Is Brain.fm's science real?+
Yes. Neural phase locking is a documented phenomenon, and Brain.fm has invested more than most competitors in building audio around it and publishing research. That said, the output is still music, with melody and rhythm your brain processes automatically, and it's a track pulled from a fixed library organized by mode rather than something built fresh around what you're actually doing that day.
How is Underlay.fm different from Brain.fm?+
The fundamental difference is that Brain.fm plays music and Underlay.fm doesn't. No melody, no rhythm, no chord changes, nothing for your brain to follow. It also asks what you're working on and how you're feeling before every session, then synthesizes a layered soundscape in real time for that specific combination. Nothing is pulled from a library, and you can adjust warmth, depth, and individual layers mid-session without breaking your focus.
How much does Brain.fm cost compared to Underlay.fm?+
Brain.fm is $14.99/month or $99.99/year. Underlay.fm is $7.99/month or $47.99/year, and also offers a $79.99 one-time lifetime plan, which Brain.fm doesn't have at any price.
Can I try Brain.fm for free?+
Brain.fm gates its trial behind account creation, so you can't hear the audio before signing up. Underlay.fm lets you start a full session immediately with no account. After that, creating a free account (still no credit card) gets you one session every day going forward.
Is Brain.fm good for ADHD?+
Brain.fm has built real trust in ADHD-focused communities over more than a decade, and that track record is worth weighing if it matters to you. Underlay.fm takes a different approach: instead of one mode that stays fixed regardless of your day, it asks how you're feeling before every session and builds around that.
Also comparing Focus@Will, Endel, lo-fi, or Noisli? See the full comparison →
Try it free. One session, no account required.
Start a free sessionThen a free session every day · Pro from $7.99/mo