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Watt4 vs JOIN
Both build a cycling plan around the time you actually have and change it when your week changes. JOIN is a paid app with its own indoor player and automatic device sync. Watt4 is free and adds a coach you can talk to. Looking for a free JOIN alternative? Here is where the two differ.
| Watt4 | JOIN | |
|---|---|---|
| Free to use | Watt4Yes: Free, no card | JOINNo: €16.99 a month or €119.99 a year, after a 7-day free trial |
| Adaptive plan | Watt4Yes: Re-plans when a ride differs from the plan, a session is missed, or your week changes | JOINYes: Adjusts after every workout from your ride data, how hard it felt and a daily readiness check |
| Plans around your availability | Watt4Yes: Time per weekday and sessions per week; mark single days off with a reason | JOINYes: Which days you can train and for how long |
| Event goals | Watt4Yes: One event, or another goal: getting faster, an aerobic base, maintaining, recovering; optional W/kg target | JOINYes: An event from JOIN's database, your own event, or a skill goal |
| AI coach chat | Watt4Yes: Ask about your training, have it build a session, or have it propose a plan change you approve | JOINNo: No chat |
| FTP without testing | Watt4Yes: Estimated from your rides; your own FTP wins if you enter one | JOINPartly: Estimated from your training (eFTP), with a 20-minute FTP test scheduled every 3 months |
| Training without a power meter | Watt4Yes: Heart-rate targets switch on automatically | JOINYes: With heart rate and how hard it felt |
| Indoor workout player (ERG) | Watt4No: No player of its own; download workouts for Zwift (.zwo) | JOINYes: Controls your smart trainer in ERG mode |
| Workouts sent to your device | Watt4Yes: To Garmin or Wahoo, with one tap | JOINYes: Automatically, to Garmin, Wahoo, Zwift and Hammerhead |
| Ride import | Watt4Partly: From Garmin | JOINYes: From Garmin, Wahoo, Zwift or Strava |
| Readiness from a wearable | Watt4No: Today's session eases when fatigue runs high or you tell the coach you're ill | JOINYes: Oura Ring, plus a daily check-in for soreness and recovery |
| Runs planned alongside your rides | Watt4Yes: Runs planned around your cycling | JOINYes: Runs planned around your cycling |
| App-store app | Watt4No: Web app you can add to your home screen | JOINYes: iOS and Android |
JOIN's details checked on 6 October 2026 against JOIN's pricing page and help centre. Apps change: check join.cc for the latest.
Which one fits you
Watt4 is the better pick if
- you don't want to pay for a training plan
- you want to ask why a session is there, and change the plan by talking to your coach
- you'd rather not ride an FTP test every three months
JOIN is the better pick if
- you want one app that also runs your indoor sessions in ERG mode
- you want today's workout on your Garmin, Wahoo or Hammerhead without doing anything
- you wear an Oura Ring and want its readiness score to steer the plan
Price
JOIN costs €16.99 a month, or €119.99 a year (€9.99 a month). There is one plan with everything in it, and new users get a 7-day free trial.
Watt4 is free while we are building it. There is no trial to run out and no card to enter.
How each plan adapts
JOIN and Watt4 start from the same idea: a plan should fit around your week instead of the other way round. In JOIN you set which days you can ride and for how long. After every workout it asks how hard it felt, and each day it asks for a short readiness check. From that, your ride data and your availability, the plan keeps adjusting.
In Watt4 you set the time you have on each weekday and how many sessions you want a week. When something comes up, you mark the day off with a reason (travel, illness, work) and the week is planned again. A ride that went harder, shorter or differently than planned also moves what comes next. With an event on the calendar, the plan works through base, build, peak and taper, and every fourth week is lighter.
A coach you can talk to
JOIN has no chat. It describes its approach as science-backed algorithms rather than AI, and you interact with the plan through settings and feedback.
Watt4 has an AI coach you can message. Ask why today is a recovery ride, what your last interval session says about your form, or for a 45-minute session because that's all the time you have. When you tell it you can't ride on Thursday, it proposes the change to your plan, and nothing changes until you approve it.
FTP without testing
JOIN estimates your FTP from your training data (eFTP), starting from a tested FTP. To keep your zones accurate, it schedules a 20-minute FTP test every three months.
Watt4 estimates your FTP from the rides you already do, by looking for genuinely all-out efforts across different durations. You don't need to schedule a test. If you know your FTP, enter it and Watt4 uses yours.
Indoor training and devices
This is where JOIN is ahead. It has its own workout player that controls your smart trainer in ERG mode, and once you connect Garmin, Wahoo, Zwift or Hammerhead, today's workout lands there automatically.
Watt4 has no workout player. You send a session to Garmin or Wahoo with one tap, or download it as a Zwift workout file. Your rides come in from Garmin.
Training by heart rate
Both work without a power meter. JOIN plans for heart-rate users and power users alike, and you choose heart rate or power when you export a workout.
Watt4 sees from your rides that you train without power and switches your targets to heart rate by itself. Workouts you send to your device then carry heart-rate targets.
Questions
Is Watt4 a free alternative to JOIN?
Yes. Watt4 is free and, like JOIN, builds an adaptive cycling plan around your availability. JOIN costs €16.99 a month or €119.99 a year. JOIN does have things Watt4 doesn't, such as its own indoor workout player and automatic workout sync to Garmin, Wahoo, Zwift and Hammerhead.
Does JOIN have an AI coach you can chat with?
No. JOIN has no chat; it adapts your plan from your ride data, how hard each workout felt, a daily readiness check and your availability. Watt4 has an AI coach you can message about your training and your plan.
Do I need to do FTP tests?
In JOIN, a 20-minute FTP test is scheduled every three months to keep your zones accurate. Watt4 estimates your FTP from your normal rides, so you don't need to test.
Can I use Watt4 on my smart trainer?
Not directly: Watt4 has no workout player of its own. You can download a session as a Zwift workout file, or send it to Garmin or Wahoo. JOIN's own player controls your trainer in ERG mode.
Can I use either without a power meter?
Yes, both. JOIN works with heart rate and how hard each workout felt. Watt4 notices you ride without power and switches your targets to heart rate automatically.
What do I need to switch from JOIN to Watt4?
A Garmin account with your rides on it. Watt4 reads your last three months, estimates your FTP and fitness from them, and plans your first week straight away.
Try Watt4 next to what you use now
Connect your account and Watt4 reads your recent rides, sets your FTP from them and plans your week. Free, no card.
Start freeJOIN is a trademark of its owner. Watt4 is not affiliated with or endorsed by JOIN.