A Carbon Tracker With No Account to Create
Why Decarbonr keeps your footprint on your iPhone
🔒 Private by design
A carbon footprint log is a detailed record of your life: what you ate, where you travelled, how warm you keep your home. Most trackers ask you to hand that over to a server before you can use them.
Decarbonr does not. There is no account to create, nothing synced to a server, and nothing sold. You open the app and start tracking.
What that means in practice
On-device
All data is stored locally on your iPhone.
No account
Start tracking instantly — no sign-up, no email, no password.
No tracking
No analytics profiles, no third parties.
No ads
Nothing to distract, nothing to sell.
Privacy without giving up the features
The usual trade-off is that a private app is a limited one. Decarbonr's tracking runs locally and still covers the whole picture:
- ✓Food, travel, energy and 12+ lifestyle categories — including heating, electricity, water, waste and digital, each colour-coded by impact.
- ✓9 transport modes with real per-kilometre emission factors from the European Environment Agency and IPCC, auto-calculating distances from city pairs.
- ✓Country comparisons and temperature impact — see your footprint against national averages, and the warming the world reaches by 2050 if everyone emitted what you do.
- ✓A Paris-aligned 2-tonne goal, with goals, streaks and achievements to build the habit.
- ✓A climate education library — timelines, explainers, calculators, country data and quizzes.
🤖 Where the AI add-on fits
Decarbonr's AI features are an optional add-on, deliberately kept separate from core tracking. They include the photo meal scanner (GPT-4 Vision), which estimates a meal's footprint ingredient by ingredient, and a barcode scanner that pulls product data from OpenFoodFacts — an open database of over 2.9 million products.
Because these features analyse an image or look up a product, they are the one part of the app that involves an external service. Keeping them optional means the privacy-first core stands on its own: if you never enable the add-on, your tracking stays entirely on your device.
Who this suits
If you have avoided footprint trackers because you did not want to open another account or hand another company a diary of your habits, this is the shape of app that removes that objection. It also suits anyone who wants to try tracking without commitment — with no sign-up, abandoning the app leaves no profile behind to delete.
The trade-off worth knowing up front: because nothing is synced to a server, your history lives on your device. That is the point, but it does mean your data is tied to that phone and your device backups.
Four questions worth asking any footprint tracker
Privacy claims are easy to make and hard to compare. These four questions cut through most of it, whichever app you end up choosing.
1. Can you use it without an account?
If sign-up is mandatory, your data is on someone's server by definition. Decarbonr requires no account at all.
2. Where do the emission factors come from?
A footprint is only as good as the numbers behind it. Decarbonr publishes its full food and transport factor tables and their sources on the research page — drawn from Poore & Nemecek (2018), the European Environment Agency, and the IPCC.
3. Does it measure the whole footprint, or one slice?
Many trackers cover food or travel alone. Since home energy is a major share of most household footprints, a tracker that ignores it will mislead you about where your own effort belongs.
4. Does it compare you to something meaningful?
A number in isolation is not actionable. Decarbonr measures against the roughly 2 tonnes per year associated with a 1.5°C pathway, and against national averages, so you can see the size of the gap.
On the last two points especially, it helps to know which changes carry the most weight before you start. Our summary of which lifestyle changes cut the most carbon works through the published evidence.
Start with today
Decarbonr is a subscription with a free trial — no account, no ads, cancel anytime. Requires iOS 17.6+.
Read our privacy policy or the science behind the numbers.