Free to Use

Your body has
a clock.
Listen to it.

A quiet browser extension that detects your circadian rhythms and surfaces practical, personal advice right when each energy window opens and closes.

Add to browser How it works

One quiet icon. Your day, named.

Circadianly maps your day into five energy windows: activation, peak, dip, rebound, wind-down. The same quiet icon updates as you move through them. Tap a window below to feel the shift.

Hours 2–6 of your day
Cognitive peak
This is your prime time. Block it for deep work, hard decisions, and focused thinking.

How to start

Two minutes from install to your first phase reading. No account, no waiting.

  1. Install the extension

    From the Chrome Web Store. One click, no permissions beyond the toolbar.

  2. Set your wake-up time

    A single field. We map the five windows around it. No questionnaires.

  3. Pin the icon

    So your current phase is always one glance away in the corner of any tab.

  4. Use it

    Open the popup any time. The card shifts with you, all day, every day.

Why Circadianly

Built quiet. Built honest.

The opposite of a habit app. No streaks, no nags, no telemetry. Just a small, well-mannered tool that respects your time and your data.

FAQ

Honest answers, plain language.

Specific questions first, broader ones at the bottom. Can't find yours? Write us.

  • Does any of my data leave the browser?

    No. Your wake time is stored in the browser's local storage. There is no account, no sync server, no analytics SDK, no third-party script. Everything the extension shows you is computed on your device, from a single number you typed in.

  • Will it work without an internet connection?

    Yes, fully. Once installed, Circadianly does not need the network to detect your phase, show the popup, or update the icon. Useful for flights, focus mode, or weak hotspots.

  • Which browsers are supported?

    Chromium browsers today: Chrome, Edge, Arc, Brave, Vivaldi, Opera. Firefox is on the short list. Safari is harder because of extension API differences and is further out.

  • Can I change my wake-up time later?

    Any time, in two clicks. Open the popup, hit settings, change the time. All five phase windows recalculate immediately. No restart, no re-onboarding.

  • Does it work for night shifts or unusual schedules?

    Yes. The schedule is anchored to your wake time, not to clock time, so the same five phases shift with you. If your wake time changes regularly, set it to your most common pattern and adjust on the rare days you need to.

  • Will I get notifications?

    Not by default, and never anything pushy. The icon itself is the notification. It changes hue with your current phase. Optional phase change reminders are in the settings if you want them.

  • Is there an account or login?

    None. There's nothing to sign up for, no email to verify, no password to forget. The extension installs and works. That is the whole onboarding.

  • Is it really free? Will it stay free?

    The current experience is free with no asterisks. If we ever release paid features, the core (phases, popup, icon) stays free for everyone. That commitment is part of why we built it.

  • How accurate is it without sensors or a wearable?

    Honest answer: it's a heuristic, not a diagnostic. Decades of chronobiology research show that the five phases follow your wake time more reliably than most people expect. Most users say it lines up with how they actually feel inside a week.

  • What is a circadian rhythm, exactly?

    A roughly 24-hour internal cycle your body runs on its own, built from hormones, body temperature, alertness, and dozens of smaller signals. It shapes when you focus best, when you slow down, and when you sleep. Circadianly is a small, daily reminder that it's there.

Start living in sync.

Free to install. No account, no data leaves your browser. Two minutes from now, your day will have a shape.

Add to browser