WattSaver for Octopus Energy

New: see what last month would have cost on Agile, Tracker or Flexible, priced on your own half-hourly usage. The price widget is now free — no account needed.

For Octopus Energy customers in the UK. Find the cheapest half-hours to run your dishwasher, washing machine or EV charger, priced on your actual tariff.

Free to use, and you don't need an Octopus account to start. Pick a device, set how long it runs, and WattSaver scans every half-hour slot to show the best start time and what it will cost. Put the free price widget on your home screen to see the current unit rate at a glance.

Works with Octopus import and export tariffs, including Agile, Tracker, Flexible, Cosy and Intelligent Octopus Go.

FREE

• Find the cheapest time to run any appliance
• Today's and tomorrow's half-hour prices
• Home screen widgets showing the current unit rate and today's prices
• Scheduling constraints: earliest start, latest finish, delayed start and finish-by times
• One saved device template
• iPhone, iPad and Mac

WATTSAVER PRO A single one-time purchase. No subscription.

• Connect your Octopus account and detect your tariffs automatically
• Smart meter electricity and gas usage by day, week, month or year
• Live demand and same-day usage with an Octopus Home Mini
• Compare one period against another — usage, cost, export profit and net value, using the tariffs active at the time
• See what that usage would have cost on a different tariff — Agile, Tracker, Flexible or any other product in your region
• Compare import and export rates
• 30-day price history with colour-coded highs and lows
• Intelligent Octopus Go smart charging slots, with alerts when Octopus adds bonus cheap slots
• Notifications when new Agile and Tracker rates are published
• Unlimited device templates
• Live usage widgets and a Mac menu bar readout
• Apple Watch app

HOME ASSISTANT, SOLAR AND BATTERY (PRO) If you run Home Assistant, WattSaver Pro connects to it and shows live grid, home, solar and battery power, plus battery charge, in its Live views and widgets.

If you use Predbat, WattSaver Pro imports your Predbat plan and uses it alongside Octopus prices — showing charge, discharge and solar windows on your charts, and letting scheduling prefer battery charging, excess solar or peak solar periods.

WattSaver does not measure your home directly: live readings come from the Home Assistant sensors you choose, and Predbat data is read from the plan URL you provide.

WattSaver is an independent app and is not affiliated with Octopus Energy, Home Assistant or Predbat.