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Free · Agile · Go · Cosy · Fixed — electricity & gas

Know when electricity is cheap. Every half hour.

Connect your Octopus API key and get a live dashboard of your tariff's prices, your real usage and costs including standing charges, cheapest-window forecasts and price alerts.

Get started — it's free See a live demo →

Read-only API access · no password, no smart-meter hardware, no card.

Price now · London

Agile Octopus · inc VAT · 7 Oct 2026, 21:40

26.87

p/kWh · Typical · until 22:00

00:00–00:30 — 27.86p 00:30–01:00 — 27.12p 01:00–01:30 — 26.28p 01:30–02:00 — 25.94p 02:00–02:30 — 26.30p 02:30–03:00 — 25.74p 03:00–03:30 — 25.82p 03:30–04:00 — 25.48p 04:00–04:30 — 26.62p 04:30–05:00 — 26.06p 05:00–05:30 — 30.14p 05:30–06:00 — 31.38p 06:00–06:30 — 36.56p 06:30–07:00 — 39.86p 07:00–07:30 — 35.80p 07:30–08:00 — 40.30p 08:00–08:30 — 34.14p 08:30–09:00 — 33.63p 09:00–09:30 — 29.16p 09:30–10:00 — 28.44p 10:00–10:30 — 28.36p 10:30–11:00 — 27.40p 11:00–11:30 — 27.04p 11:30–12:00 — 24.75p 12:00–12:30 — 23.46p 12:30–13:00 — 23.06p 13:00–13:30 — 23.00p 13:30–14:00 — 22.40p 14:00–14:30 — 23.62p 14:30–15:00 — 23.06p 15:00–15:30 — 25.50p 15:30–16:00 — 25.66p 16:00–16:30 — 40.34p 16:30–17:00 — 43.06p 17:00–17:30 — 46.74p 17:30–18:00 — 47.74p 18:00–18:30 — 47.50p 18:30–19:00 — 48.22p 19:00–19:30 — 32.05p 19:30–20:00 — 31.52p 20:00–20:30 — 28.66p 20:30–21:00 — 27.78p 21:00–21:30 — 28.30p 21:30–22:00 — 26.87p 22:00–22:30 — 24.84p 22:30–23:00 — 21.60p 23:00–23:30 — 20.02p 23:30–00:00 — 16.45p 00:00–00:30 — 16.56p 00:30–01:00 — 16.86p 01:00–01:30 — 15.62p 01:30–02:00 — 16.02p 02:00–02:30 — 15.76p 02:30–03:00 — 16.46p 03:00–03:30 — 15.91p 03:30–04:00 — 15.05p 04:00–04:30 — 15.95p 04:30–05:00 — 16.57p 05:00–05:30 — 18.00p 05:30–06:00 — 20.53p 06:00–06:30 — 24.04p 06:30–07:00 — 29.66p 07:00–07:30 — 29.66p 07:30–08:00 — 30.84p 08:00–08:30 — 28.87p 08:30–09:00 — 27.90p 09:00–09:30 — 27.65p 09:30–10:00 — 23.76p 10:00–10:30 — 20.70p 10:30–11:00 — 19.56p 11:00–11:30 — 18.06p 11:30–12:00 — 18.17p 12:00–12:30 — 17.23p 12:30–13:00 — 17.72p 13:00–13:30 — 16.92p 13:30–14:00 — 17.76p 14:00–14:30 — 19.18p 14:30–15:00 — 18.84p 15:00–15:30 — 19.62p 15:30–16:00 — 22.46p 16:00–16:30 — 36.52p 16:30–17:00 — 40.52p 17:00–17:30 — 43.87p 17:30–18:00 — 45.66p 18:00–18:30 — 48.11p 18:30–19:00 — 49.25p 19:00–19:30 — 35.17p 19:30–20:00 — 34.25p 20:00–20:30 — 33.38p 20:30–21:00 — 28.79p 21:00–21:30 — 29.45p 21:30–22:00 — 24.92p 22:00–22:30 — 23.51p 22:30–23:00 — 19.41p

TodayTomorrow23:30

Best 3h window → tomorrow 01:00–04:00 · 15.80p avg

How it works

Set up in two minutes

No installation, no hardware, nothing to configure on your meter.

01

Create a free account

An email and a password — that is all we keep about you. It secures your connection and usage history.

02

Paste your API key

Read-only, from your Octopus dashboard under Personal details → API access. We detect your meters, tariff and region — nothing else to type.

03

Watch the pennies

Live prices, what you actually spent, and a nudge before the expensive hours start.

Features

What you get

Live half-hourly prices

Every settlement period for today and tomorrow, the moment Octopus publishes it.

Cheapest-window finder

The cheapest run of consecutive half hours still to come — 30 minutes to 6 hours.

Usage and real costs

Your smart-meter readings priced against your actual tariff, standing charge included.

Alerts

Peak starting soon, plunge pricing, cheap windows, or a price threshold you pick.

Usage profile

Your average half-hourly shape, so you can see which habits are costing you.

Gas too

Gas unit rates and standing charges alongside electricity, on the same dashboard.

Prices and guides

Start where you are

Every region, every current Octopus tariff, and plain explanations of the bits of a UK energy bill nobody ever explains.

Your region

All fourteen regions →

Octopus tariffs

Every tariff explained →

Guides

All guides →

FAQ

Questions

Is it really free?

Yes. Live prices, the cheapest-window finder, your usage and costs, and alerts are all free, with a year of history.

Is my API key safe?

We only ever read with it — your tariff, your meters and your readings, nothing else. Treat it like a password, because it identifies you to Octopus: revoke it from your Octopus dashboard whenever you like, and delete everything we hold in one click.

Do I need a smart meter?

Not for prices — those work for everyone. Usage and cost figures need a smart meter sending half-hourly readings to Octopus.

Which tariffs are supported?

Agile, Go, Cosy, Flux and Snug, plus Flexible and the current Fixed products, for electricity and gas. Whatever the tariff shape, prices land on the same half-hourly grid.

Which region am I in?

Great Britain has fourteen electricity regions, and your unit rate depends on yours. It is the first two digits of the MPAN on your electricity bill, and it is detected automatically if you connect an Octopus account.

Are you Octopus Energy?

No. halfhourly.uk is an independent tool built on the public Octopus API. It is not affiliated with, endorsed by, or connected to Octopus Energy.

Stop guessing when power is cheap.

Free to use, and you can delete everything in one click.

Get started — it's free