Privacy policy

Applies to the Sumico desktop app for Windows and macOS and to this website. Last updated 15 October 2026.

Sumico has no account, no sign-in and no server of its own. What you type stays on your computer. The only thing that ever leaves it is a three letter currency code, sent to fetch an exchange rate.

What Sumico stores, and where

Everything Sumico keeps is written to the app's data folder on your own computer. Nothing is uploaded, and there is no sync between devices.

• Your documents: the text you type and its title.
• Your preferences: theme, precision, thousands separator, base currency, angle unit, locale, rate source and font size.
• Session state: which document was open last, so it reopens where you left it.
• A cache of exchange rates, with the time they were fetched.

What Sumico sends

Exchange rate requests, and nothing else. Sumico requests rates from three services, and which of them is used depends on your settings and on what your document mentions:

• open.er-api.com: daily rates for national currencies. This is the default source.
• api.frankfurter.dev: European Central Bank reference rates, used instead of the above if you select it in Preferences.
• api.coingecko.com: cryptocurrency prices, requested only when a line in your document mentions a crypto ticker such as BTC or ETH.

Each request carries the three letter code of your base currency, and for the crypto service also the tickers your document uses. It carries nothing else: not your text, not your document titles, not an identifier. Rates are requested when Sumico starts and about every six hours after that, plus whenever you change the rate source or the base currency, or press Refresh rates now.

As with any request to any website, the service receiving it can see the network address it came from, and may log it under its own policy. Their policies: ExchangeRate-API, Frankfurter, CoinGecko.

Sumico also ships with a dated snapshot of rates inside the app, so currency lines still resolve with no connection at all.

What Sumico does not do

• No analytics, no telemetry, no crash reporting, no advertising and no third-party trackers in the app. This website counts visits, as described below, and shows no advertising.
• No account, no sign-in, no sync, no cloud storage.
• No AI and no API keys. Calculation happens on your computer.
• No selling of personal data, no transfer of it to anyone, and no use of it for anything beyond the calculator itself.

This website

The calculator on this website runs in your browser, with a rate snapshot built into the page, and sends nothing anywhere. If your browser's language or time zone suggests you may prefer the Russian version, the page offers it; that check runs in your browser, and your answer is remembered only there. The web server keeps a standard access log: address, time, page requested and browser name. The counters are described under Website statistics.

Website statistics

This website, and only the website, counts visits with Google Analytics 4 (Google) and Yandex Metrika (Yandex). The Sumico app contains neither and sends nothing to them.

The counters receive: the pages you view, the site that sent you here (its host, and the utm_ tags if the link has them), your approximate location derived from your network address, your browser, device type and language, the time of the visit, your clicks on the Buy and Download buttons, the payment method you pick, and the fact that a purchase was completed. Both counters set cookies to tell visits apart.

They never receive what you type into the calculators on the page, your email, your card details, license keys or download links. The number of a completed order is sent once, as the transaction ID of the purchase. Session recording (Webvisor), click maps, advertising features and audience building are off. If your browser sends Do Not Track or Global Privacy Control, the counters are not loaded at all.

Google and Yandex process this data under their own policies: Google, Yandex. A browser extension that blocks trackers also blocks the counters, and the website works the same.

Phone app waitlist and testing

If you join the waitlist or the early testing group for the phone app, we keep the email, the optional name and, for testing, the device you chose, only to write to you about the app. To have them deleted, write to hello@sumico.app.

Keeping and deleting your data

Your documents stay until you delete them, inside Sumico or by removing its data folder. Because nothing is uploaded, there is no copy elsewhere for anyone to delete, and no request you need to send to have one removed.

Children

Sumico is a calculator. It is not directed at children, and it collects no personal information from anyone, of any age.

Changes

If what Sumico stores or requests changes, this page changes with it, and the date at the top moves.

Contact

Sumico is made by Maksim Golub. Questions about this policy: hello@sumico.app. General help lives on the support page.