Privacy policy

Last updated 11 November 2026

Who runs Deficitly

Deficitly (deficitly.com) is run by Andris Zarins, Latvia, who is responsible for the data described here (the "data controller" under the EU General Data Protection Regulation, GDPR). To ask anything about your data, use the contact form.

What stays on your device

The calculator and the tracker run in your browser. Everything you type in is saved in your browser's own storage on this device. Unless you turn on sync, none of it is sent to us:

• your profile and settings: sex, age, weight, height, body fat, steps, workouts, goal, units and theme (browser storage named tdee:…);
• your weigh-ins, daily calories, food log, the foods you create and your favourites, and the keys for sync if you use it (a browser database named tdee);
• a copy of the app's own files, so it works offline (caches named tdee-cache-…).

Weight and food logs are health data, which the GDPR protects specially. Because they stay on your device, or travel only encrypted if you use sync, we can't see, sell or lose them. The other side of this: if you clear your browser data or lose the device, they are gone, so export a backup now and then. A backup file stays wherever you save it.

The barcode scanner uses your camera only on the device: the picture is read in the browser and never uploaded. The share image is drawn on the device too; it goes only where you choose to share it.

To delete everything, open Settings (the gear at the top of the app) and tap Clear all data, or clear this site's data in your browser settings. Uninstalling the home-screen app removes it too. If sync is on, deleting the synced copy on our server is a separate step (see Sync between your devices).

What reaches our server

Like every website, our server receives a request each time your browser loads a page or file. These requests are written to the server's access log with your IP address, the date and time, the address requested, the page you came from (if your browser sends it) and your browser's name and version. Some requests say a little about how you use the app:

• Food search and barcodes. Searching products by name or looking up a scanned barcode sends the words you typed or the barcode number to deficitly.com, so they appear in the log. Nothing else from your food log is sent, and there are no accounts, so a search isn't linked to you beyond the IP address.
• Screen counts. The first time you open the Food or Progress screen in a visit, the app loads a tiny empty file. It carries no ID; it only lets us count how often those screens are used.
• App opens. The installed app opens the address /?src=app, so we can count app starts.

We use the logs to keep the site running and secure and to count visits in total (for example, how many people used the food search this week). To tell people from bots we look up the network name of IP addresses (reverse DNS). We don't build profiles, combine the logs with other data, or share them with anyone.

How long: the server deletes its access logs after 14 days. A copy used for traffic statistics is kept on our own computer for at most 12 months and then deleted.

Legal basis: our legitimate interest in running a secure website and knowing whether it is used (GDPR Article 6(1)(f)).

The site runs on a server we operate ourselves in Latvia; no hosting company, CDN or analytics service processes these requests. All connections use HTTPS.

Sync between your devices

Sync is off until you turn it on in Settings → Sync devices. When it is on, your linked devices keep the same weigh-ins, food log, your own foods, recipes, saved meals, meal plans and calculator settings by sending them through our server. Not synced, so they stay on each device: the theme, small view settings, shopping list ticks and the weight loss challenge (which holds other people's names and weights).

End-to-end encrypted. Your data is encrypted on your device before it is sent, with a key made from your sync code. Neither the key nor the code ever reaches our server unencrypted. Our server, the same one we run ourselves in Latvia, stores only:

• the encrypted items, each under a random-looking name, so we can't even tell a weigh-in from a recipe (a deleted item is replaced by an encrypted note that it was deleted, so your other devices delete it too);
• a random ID for your synced copy and a scrambled (hashed) form of its access token;
• when the copy was created and last used, and how many items and bytes it holds.

There is no account, name or email behind a synced copy, and the names of your linked devices ("iPhone · app") are encrypted too. We have no way to unlock a synced copy, and neither would anyone who broke into our server.

Linking a device. The QR code and the link work once, for 15 minutes. They carry a one-time key that never reaches our server, and the server deletes the linking entry as soon as it is used or expires. The 6-digit code is easier to type but weaker: a linking code is only safe for the 15 minutes it lives. With a million possible codes, whoever runs the server could in principle try them all in that time and unlock your synced copy. We don't, and to stop outsiders guessing, the server allows each connection only 20 tries an hour. If you'd rather not rely on that, link with the QR code or the link.

The recovery code. Under Manage you can show a recovery code. Anyone with it can read your synced data, so keep it somewhere safe. We can't recover it for you: if you lose every device and the code, nobody can open the synced copy, us included.

How long: the synced copy is kept while you use it. A copy that no device has synced for 18 months is deleted automatically, with everything in it.

How to delete it: in Settings → Sync devices → Manage, Delete synced copy removes it from our server at once; every device keeps its own data and stops syncing. Stop syncing on this device only unlinks that device, and the synced copy stays for your other devices. If you lost every device but kept the recovery code, link a new browser with it and delete the copy from there. Because we can't tell which synced copy is yours, we can't find or delete one on request; an unused copy goes on its own after 18 months.

The server log: sync requests are written to the access log like any other request (the address /api/sync.php, your IP address, the time and your browser's name) and are kept as described above. Nothing secret is in the address, and what a request carries is never logged. To limit abuse, the server counts requests per connection under a scrambled form of your IP address that changes every day and is deleted after 2 days. IP addresses are never stored with a synced copy.

Legal basis: encrypted data we can't read is still personal data, so sync only starts when you ask for it. Turning sync on is your explicit consent to us keeping the encrypted copy (GDPR Article 6(1)(a) and, because it is health data, Article 9(2)(a)). You can withdraw it at any time with Delete synced copy.

The contact form

When you send a message, we store your name (if you give one), your email address, the message and the time it was sent, in a file on our server. We use them only to read and answer your message, and we never share them. Messages are deleted after 12 months, or sooner if you ask. Your IP address is not saved with the message: to stop spam, the form keeps a scrambled (hashed) form of it for one day, which can't be turned back into the address. Legal basis: answering your request (GDPR Article 6(1)(b), and 6(1)(f) for the spam protection).

Other companies we share data with

None, with one exception:

• Open Food Facts. Product data comes from Open Food Facts, a free food database. We keep our own copy on our server, so normally your searches and barcodes go only to us. If our copy can't answer, the app asks Open Food Facts directly for that one barcode, and their server then sees the barcode number and your IP address. Their privacy policy applies to that request.

Deficitly loads no ads, analytics, social media buttons or tracking pixels. Fonts and all other files come from deficitly.com itself. Links to other websites (studies, Open Food Facts) take you to sites with their own privacy rules.

Cookies

Deficitly sets no cookies. The browser storage described above holds only what you enter and is needed for the app to work, so no consent banner is required.

Your rights

Under the GDPR you can ask to see, correct or delete the personal data we hold about you, object to how we use it, or ask us to limit it. In practice we hold very little: server logs for up to 12 months, any messages you sent us and, if you use sync, an encrypted copy we can neither read nor link to you (how to delete it). Your device data is already fully in your hands. Write to us through the contact form; we answer within one month. You can also complain to a data protection authority: in Latvia that is the Data State Inspectorate (Datu valsts inspekcija), or the authority in the EU country where you live.

Children

Deficitly is meant for adults and isn't aimed at children under 16.

Changes to this policy

If how Deficitly handles data changes, we update this page and the date at the top.