Comparison

GridCarbon vs Octopus Watch

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

GridCarbon

Monitor the real-time carbon intensity of the UK electricity grid. Understand how electricity generation sources change and identify times when using power is more environmentally friendly. Reduce your carbon footprint by shifting energy consumption to periods of lower grid emissions.

Highlights
  • Real-time carbon intensity updates
  • Traffic light indicator for intensity levels
  • Generation mix summary
  • 24-hour carbon intensity plot
  • Interactive generation mix chart
Features
Read full description

Track the carbon intensity of the GB electricity grid on your iPhone or iPad Demand for electricity varies throughout the day, and thus, the mix of generators supplying this electricity continually changes. As a result, the carbon intensity of the electricity – the quantity of CO2 produced for 1 kWh of electricity consumed – also varies continually. Deferring your use of electricity to off-peak times, when the carbon intensity is low, can help reduce your carbon footprint. Features: - Data updated every 5 minutes. - Display of instantaneous carbon intensity (gCO2/kWh). - Traffic light indicator to highlight period of low and high carbon intensity. - Generation mix summary showing total and percentage supply by type. - Line plot showing carbon intensity over the previous 24 hours. - Interactive bar chart showing the generation mix over the previous 24 hours.

About

Octopus Watch

Easily manage your Octopus Energy tariffs, track electricity rates, and identify optimal times to use appliances or charge your EV. Offers insights into usage, weather impacts, and export earnings. Optional subscription unlocks advanced features like 48-hour rate predictions and carbon integration.

Highlights
  • Track current and upcoming electricity rates
  • Identify cheapest times for appliances/EV charging
  • View historic usage and micro metrics
  • Receive rate change alerts
  • Compare tariffs
  • Export data to CSV
  • 48h Agile rate predictions (subscription)
Features
Read full description

Octopus Watch is the easiest tool to manage the (smart) tariffs provided by Octopus Energy in the UK. Octopus Watch is a paymium app for iOS offering both a standard version as a one-time purchase, and an optional subscription with additional features. Ready to supercharge your savings? Save significantly on your electricity bill, regardless of whether you're on Agile, Go, Cosy, Flux, Tracker, or any fixed tariffs (basic or eco 7). Thinking of joining Agile? Log into the app with just your postcode and check out local rates. If you want to see your consumption history, you'll need an Octopus Energy account and an active smart meter. Please note that support for Intelligent and Intelligent Go is currently limited, with only default off-peak times available. For the latest status on tariff support check out the wiki: https://wiki.smarthound.uk/octopus-watch/tariffs/ . With the standard version of Octopus Watch, you'll have all the tools at your fingertips to effectively manage your tariff: • View your current rates in an instant (including for gas trackers). • View your current electricity rates directly on your Apply Watch! • See all your upcoming rates in an easy chart and table. • Instantly get the cheapest times to run appliances or charge your EV, and save big! • Use the beautiful widget for current and upcoming prices on your home screen. • Receive alerts when the next day's Agile rates are available. • See your historic day-by-day usage. • Use the new micro metrics to quickly see trends in your usage. • See when your meter fails and how much data is missing. • Understand how weather influences your usage. • One tap comparison to see how your tariff compares to Agile, Go, and SVT. • Check your earnings from export (only available with an export meter). • Various options to change the app defaults to best suit your needs! • Export cleaned data to CSV for easy use in other apps such as Microsoft® Excel®. Want even more? A single subscription gets you access to these amazing features: • Up to 48h Agile rate predictions – plan your usage effectively and save even more! • If you have an export meter, also receive Agile export rate predictions. • Access 7-day weather forecasts across Great Britain for even better planning. • Instant notifications when next day's Agile prices fall below your chosen threshold. • Identify optimal half-hour blocks throughout the day to charge your EV or run appliances. • Carbon integration - see your environmental impact both now and in the past. • View your electricity generation regionally or nationally, and adjusted to your usage. • Choose the best slot based on either price or lowest carbon emissions on the grid. • One tap comparison to see how your tariff compares to most smart tariffs. • Advanced micro metrics over 14 or 28 days, including subscription-only metrics. • Day details – see your exact usage along with numerous statistics on a day-by-day basis. • Day details – see exactly which data is missing when your meter stops reporting. • Micro-optimise your usage with half-hour details within the app. • Generate straightforward electricity reports for any period in the last year. • Generate detailed gas reports, including heat pump efficiency information, for the last year. Thanks to Family Sharing you can install the app on all devices within the same family. Install it on your iPhone for an easy pocket reference, run it from your iPad to see the beautiful rate graph and double column table, or see the current rate with a flick of your wrist on your Apple Watch with dozens of complications to choose from. The choice is yours! Octopus Watch also supports subscription sharing, so one subscription gives you access to all the extras on all the iPhones and iPads in your household.

Screenshots

GridCarbon3 screens
Octopus Watch4 screens

Verdict

The call

The clearest difference is price: GridCarbon at Free against Octopus Watch's $1.99. GridCarbon also leads on in-app purchases (none vs 2) and review sentiment (76% vs 65%). Octopus Watch's advantage is rating (4.0 vs 3.2) and update cadence (every 3 weeks vs every 4 months). On ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

GridCarbon is free to download; Octopus Watch costs $1.99 up front. Octopus Watch sells 2 in-app purchases, starting at $1.99 per month. GridCarbon asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Octopus Watch holds the better App Store score, 4.0 against 3.2. That said, the two scores are not equally well evidenced: GridCarbon has 6 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 76% of GridCarbon's written reviews are positive against 65% of Octopus Watch's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

GridCarbon ships an update every 4 months, Octopus Watch every 3 weeks. The most recent releases landed on June 8, 2026 and September 23, 2026 respectively.

Scorecard8 real differences · 2 level
GridCarbon versus Octopus Watch: the parameters behind the verdict, then further details
ParameterGridCarbonOctopus Watch
PriceFree — better$1.99
Rating3.2 (6 ratings)4.0 (1 ratings) — better
Positive reviews75.7% of reviews — better64.6% of reviews
Number of ratings6 — better1
Update frequencyEvery 4 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, Apple Watch
Requires iOS12.0 — better16.1
Further details — not scored
Size10 MB18 MB
Age rating4+4+
DeveloperAlex RogersKim Bauters

Customer experience

GridCarbon

All ratings6 ratings
Positive50.0%
Neutral16.7%
Negative33.3%
Written reviews37 reviews
Positive75.7%
Neutral10.8%
Negative13.5%

Octopus Watch

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews79 reviews
Positive64.6%
Neutral10.1%
Negative25.3%

In-app purchases

None

GridCarbon

No in-app purchases

2 purchases

Octopus Watch

Subscriptions2
  • 1 Month Subscription$1.991 Month
  • 1 Year Subscription$11.991 Year

Questions

Is GridCarbon free?
GridCarbon is free to download, with no in-app purchases.
Is Octopus Watch free?
Octopus Watch costs $1.99, and also offers in-app purchases.
Which has better reviews, GridCarbon or Octopus Watch?
Octopus Watch is rated higher. GridCarbon averages 3.2 out of 5 from 6 ratings, while Octopus Watch averages 4.0 from 1 ratings.
Do GridCarbon or Octopus Watch have ads?
Neither GridCarbon nor Octopus Watch shows ads.
Which is updated more often, GridCarbon or Octopus Watch?
GridCarbon ships an update every 4 months, and Octopus Watch every 3 weeks. Most recently, GridCarbon was updated on June 8, 2026 and Octopus Watch on September 23, 2026.

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