You're invited on the ride.

Your group uses Kardiacs to talk and share one map with zero bars. Get it before you meet — it's free, no account needed.

At the ride: scan the leader's QR code. No account needed.

Ride together

Your group, in your ear. No signal. No server.

  • Talk hands-free

    Unmute and the group hears you. Push-to-talk if you prefer.

  • One live map

    Everyone’s dot, on every phone. See who’s behind.

  • Words, too

    What you say is typed into the chat, so a rider out of voice range still reads it.

  • Stretches with the group

    Up to 200 m rider to rider, and further as phones relay it down the line.

Join in five seconds: scan the leader’s QR code. No account.

How it works →

Voice: iPhone 12 or later on iOS 26.4+ with other iPhones; Android 13+ with Wi-Fi Aware with other Androids. Map, chat and photos work between any phones. Range varies with terrain. Encrypted between phones — nothing reaches us.

A Kardiacs group chat on a climb: messages from Ben and the rider, with both riders' microphones open
A live run in Kardiacs navigating a trail loop, with the next turn called and the pace on screen

Ride in a minute.

  1. Download. No account, no sign-up wall.

  2. Tell it your age and weight — or connect Health — for zones from day one.

  3. Pick Explore, Commute or Indoor. Go.

Bringing history? Import your Strava or Garmin archive, or any FIT file.

Saturday’s better with everyone on it.

or

Why is it free?

Free, paid for by ads. Nothing to buy. The ads pay for the maps and servers.

Ride in a minute.

  1. Download. No account, no sign-up wall.

  2. Tell it your age and weight — or connect Health — for zones from day one.

  3. Pick Explore, Commute or Indoor. Go.

Bringing history? Import your Strava or Garmin archive, or any FIT file.

Questions

Is it really free?

Yes. Ads pay for the maps and servers. There is no paid tier and nothing to buy.

Do my friends need the app too?

Yes — it is phone to phone. They join by scanning your QR code, with no account. Riders can be up to 200 m apart, and further as phones relay it along the group.

Does it work on Android?

Yes. The map, chat and photos work between any phones running Kardiacs. Group voice works iPhone to iPhone (iPhone 12 or later, iOS 26.4+) and Android to Android (Android 13+ with Wi-Fi Aware).

Does it work with my trainer, watch or bike computer?

Bluetooth FTMS and Wahoo smart trainers, power meters and heart-rate straps pair directly. There is an Apple Watch app. Routes and workouts go out to your bike computer, and the rides it records come back in.

Do I need an account?

No. There is no sign-up wall. Sign in with Google or Apple only when you want your history, routes and gear to follow you between devices and into the web planner.

More questions, answered →

Saturday’s better with everyone on it.

or