The Moveee team
Free coaching · a real route for every ride
ERG mode is the feature that makes structured indoor training almost effortless to execute: you set a target wattage, and the trainer holds you there no matter your cadence. It used to require installing a desktop app. Not any more — ERG mode in the browser works on any modern smart trainer, from a single tab, for free. Here's how.
What ERG mode actually does
Normally your power depends on how hard you push and what gear you're in. In ERG mode, you hand that job to the trainer: you name a target, and the trainer continuously adjusts its own resistance to keep you at that exact wattage. Spin at 85 rpm or 95 rpm — the watts stay put. Your only job is to keep pedalling.
You set a target
Say 220 W for a 5-minute interval. The workout knows the target for every block.
The browser sends it to the trainer
Over Web Bluetooth, the tab tells the trainer: hold this rider at 220 W.
The trainer adjusts resistance
Pedal slower and it makes it harder; pedal faster and it eases — to keep you at 220 W.
You just turn the pedals
No shifting, no chasing a number. Hit the interval, recover, repeat.
Yes, the browser can really do this
The same standard that lets a web page read your power (FTMS / Fitness Machine Service) also lets it command the trainer's target. So a browser tab in Chrome or Edge can drive ERG mode exactly like a native app — no install, no dongle. If your trainer does ERG in its own app, it'll do ERG in the browser.
Escaping the "spiral of death"
One thing worth knowing: if you let your cadence fall too far in ERG mode, the trainer keeps cranking resistance to hold the watts, which slows you further — the dreaded spiral. The fix is simple: keep your cadence up, and if you do bog down, ease off for a second or shift so the trainer can recover. Good apps also let you nudge the target on the fly.
ERG in the browser, on a real road, free
Moveee Indoor holds ERG targets from a browser tab on any standards-based smart trainer — so your intervals are precise — while you ride your own saved routes rebuilt in 3D from real map data. Nothing to install, free while in alpha, and rides save with full power data to your Moveee plan and Strava.
Set the target, keep the legs turning, let the trainer do the rest. That's ERG — and it lives in a browser tab now.
Sources 4
Where this article summarises a study, the study itself is linked — not a write-up of it.
- 1 Fitness Machine Service 1.0 (FTMS) specification · Bluetooth SIG · 2017
- 2 Web Bluetooth (Draft Community Group Report) · W3C Web Bluetooth Community Group · 2024
- 3 Web Bluetooth API — browser compatibility · MDN Web Docs · 2025
- 4 Communicating with Bluetooth devices over JavaScript · Chrome for Developers · 2024
Your own roads, indoors, in a browser tab
Moveee Indoor pairs your smart trainer over Bluetooth and rebuilds a route you have saved as a 3D road — real gradients, ERG for the intervals, and the ride saved with full power data. Nothing to install. Free while it is in alpha.
Start an indoor rideKeep reading
Can you really train indoors in a browser? How Moveee Indoor works in 2026
"In the browser" used to mean toy-grade. Not any more. Here's how a browser now pairs your trainer, holds your watts and renders a real 3D world — and what still needs a native app.
How to use your Wahoo KICKR without Zwift (a free browser app)
Your Wahoo KICKR doesn't need Zwift — or any subscription — to give you a proper session. Here's how to use a KICKR (or KICKR Core, Snap and Move) with a free browser app that controls resistance, holds ERG targets and saves to Strava.
ERG mode explained: when to use it, when to turn it off
ERG mode holds your watts so you don't have to. Here's how it actually works, how to escape the dreaded spiral of death, and the sessions where you're better off without it.
A free app for the Zwift Hub and Zwift Ride (yes, without Zwift)
Zwift's own trainers speak the same standard Bluetooth as everyone else's — which means a Zwift Hub or Zwift Ride works perfectly well without a Zwift subscription. How to pair Zwift hardware with a free browser app, what works (ERG, resistance, power), and the honest caveats around buttons and firmware.
A free app for Saris and JetBlack trainers (in your browser)
A Saris H3 or a JetBlack Volt doesn't need a subscription to earn its keep — both brands speak standard Bluetooth FTMS, so a browser tab can control resistance, hold ERG targets and record the ride. Model-by-model support, pairing steps, and the honest caveats for older wheel-on units.
How to connect a smart trainer to your browser with Web Bluetooth
Your browser can talk to your smart trainer directly — no app, no dongle, no ANT+ stick. Here's how Web Bluetooth pairing works, what it supports, and how to fix it when it won't connect.
Can you use a spin bike with cycling apps? What works and what doesn't
The gym-style spin bike in your spare room and the cycling apps on your laptop live in different worlds — but there are honest bridges between them. What a dumb spin bike can and can't do, the sensors that unlock app compatibility, which smart bikes broadcast openly, and when a used smart trainer is simply the better buy.
Turn a dumb trainer smart with a power meter and your browser
You don't need to buy a smart trainer to train with power indoors. Here's how to turn a dumb trainer smart with a power meter (or speed sensor) and a free browser app — including how virtual power fills the gap if you have neither.
An indoor cycling app for Windows with nothing to install
No admin rights, no 12 GB download, no launcher updating itself before every session. Here's how to run a full indoor cycling app on Windows with nothing to install — a browser tab, your smart trainer, and a real 3D road.
10 changes that make you a genuinely faster cyclist
Ten improvements ordered by return on effort — only some of which involve producing more watts. Plus four things you can fix in your garage this afternoon for free.
Gears explained: what the numbers on your cassette mean
Tooth counts to gear ratios to speed at a cadence, why steps matter more than the number of gears, what cross-chaining costs, and how to pick a gear on a climb.
Zone 2 training on a smart trainer: how to actually stay in zone
Everyone agrees Zone 2 builds the engine — and almost nobody actually rides it, because outdoors every junction, hill and ego bump pulls you out of zone. On a smart trainer with ERG mode the discipline problem disappears. How to set the right watts, manage drift, and make 90 steady minutes genuinely bearable.