Live since May 2026.
Let's keep going.
Plus is how we keep building Circadia without giving up the promise that started it.
A little transparency.
I have N24. I built Circadia because I needed it to exist: a place where a drifting body clock isn't treated like bad data. I build the app and its Smart forecast. Jon handles everything underneath — the databases, the servers, and the machine learning behind Adaptive. We're two people at a kitchen table, making the thing we wish someone had made years ago. It's just us, not a company or a hidden team.
Circadia Plus is here. Some features have moved behind a paywall, and I want to be upfront about why. I wish I could keep every feature free for everyone. More than that, though, I want Circadia to still be here in five years, doing what it was built to do.
Adaptive learns your rhythm specifically, and that takes serious machinery. We've spent about $8,000 on compute hardware, and it's nearly maxed out — we've literally been renting extra compute to keep the training runs going while the next machine waits on a good month. Another $5,000 has gone to everything else an app quietly costs. And then there's Google's required security audit just for Fitbit access: $500–$5,000 every year, which we have not paid. That is why there is no live Fitbit sync. Fitbit history still imports from a Google Takeout export.
So far, every dollar has come from the two of us, plus about $150 in donations that we're so grateful for. That's carried us this far, but we've now put in about everything we comfortably can — and for Circadia to have a future, it needs to start covering its own costs. I'd rather tell you that plainly than pretend everything's fine. The features that cost real money to run are now Circadia Plus. The core stays free; Plus is how the whole thing gets a future.
And there is so much worth building toward. Every research sign-up grows the N24 cohort. In the long run, that research can change what medicine knows about N24 and help us earn grants that can fund this work properly. Grants take years. Plus is the bridge.
If you choose Plus, you're helping the forecasts keep running, helping us build what comes next, and helping Circadia stay open to people who can't pay. Our promises remain the same: no ads, ever, and your data is never for sale. The core stays free. Sleep data is health data, and it belongs to you.
Whether or not you subscribe, you can still log without limits and understand your rhythm — and use Circadia every day.
Plus and Supporter open the same Circadia. Supporter helps more. Lifetime is one payment, forever.
Plus
- Adaptive, trained on you — personal training runs every two weeks, so the model is based on your rhythm and nobody else's
- The full 14-day forecast, from both models
- Event Check — see how any event lands against your forecast
- Your forecast, synced right into your real calendar
- Wake reminders that move with your rhythm
- Oura sync
- Advanced analytics & pattern detection
- Unlimited members in your Circle
- Premium themes & the full Tessera picture set
Supporter
- Everything in Plus — no gatekeeping, no extra access tiers
- A Supporter badge
- You directly help cover the hardware, the servers, and the accounts of people who can't pay
Lifetime
- Every Plus feature — and every future one — forever
- A Lifetime badge
- One payment on a good month, and you never think about it again
Everyone gets 30 days of Plus free when it launches on the web — no card, no auto-charge, no tricks. Decide with the real thing.
| At a glance | Free | Plus |
|---|---|---|
| Unlimited logging & history | ✓ | ✓ |
| Clock, drift chart, & calendar | ✓ | ✓ |
| Doctor's report & report card | ✓ | ✓ |
| Tonight's prediction peek | ✓ | ✓ |
| Import, export, & Apple Health | ✓ | ✓ |
| Period & cycle tracking | ✓ | ✓ |
| Full 14-day forecast, both models | — | ✓ |
| Adaptive — personal training runs | — | ✓ |
| Event Check + calendar sync | — | ✓ |
| Wake reminders that move with you | — | ✓ |
| Wearable sync (Oura) | — | ✓ |
| Advanced analytics & lens extras | — | ✓ |
| Daily games & Community | ✓ | ✓ |
| Premium themes & the full Tessera set | — | ✓ |
| Circle sharing | 1 person | Unlimited |
No ads. Ever.
Not on the free plan, not anywhere. Your 3am is not a billboard.
Never for sale
Your data goes to no advertiser, no broker, no one. Sleep data is health data — and it's yours.
Privacy first
No tracking in the app. Export everything whenever you want. Delete your account and it's actually gone.
The core stays free
Understanding your rhythm will never go behind the paywall. That's the founding promise.
If Plus would help but the price doesn't fit, message the 🔔 bell. No proof needed. We'll make it work.
