Privacy policy
Last updated August 2026. This describes what nanofile.io does with your data, in plain terms. Where something is a limitation rather than a promise, it says so.
The short version
Your files are compressed by your own browser, on your own device. They are never sent to us, because there is no endpoint to send them to. We do collect anonymous usage analytics about how the site is used, which is described in full below.
Your files
When you drop a file into any compressor here, it is read into memory by the page and processed by code running in your browser. No copy is transmitted anywhere. There is no upload route in the application, no storage bucket behind it, and no queue. You can confirm this yourself: open your browser's network tools, compress something, and watch that no request carries the file. Disconnecting from the network after the page has loaded also works, and the compressors keep running.
Because your files never reach us, we cannot read them, scan them, retain them or hand them to anyone else. This is a property of how the site is built rather than a policy we have chosen to follow, which is the strongest form the guarantee can take.
Files you compress are held in your device's memory only for as long as the page is open. When you leave or reload the page, they are gone.
What is stored on your device
Three things, all local to your browser and none of them sent to us:
- Your theme choice. A single value under the key
nf-themein local storage, so the site does not flash the wrong colours when you return. - Files in transit between pages. When you drop a file on the home page, it is parked briefly in your browser's IndexedDB so the compressor page can pick it up after navigating. It is removed once collected, and it never leaves your device.
- Analytics cookies. Set by Google Analytics, described next.
Analytics
We use Google Analytics 4 to understand which tools people use and where the site is failing them. This is the one part of the site that sends data to a third party, so it is worth being precise about what that data is.
We never send file names, file paths, file contents, or anything derived from the contents of your files. The code strips any parameter whose name suggests it could carry one before an event is sent. Sizes and durations are sent as coarse bands rather than exact figures, so a single event cannot be matched back to a specific file.
These are all the events the site can send, and everything each one carries:
| Event | What it records |
|---|---|
file_selected | That a file was chosen, its format, and a coarse size band such as 1-5MB. |
format_unsupported | The format of a file we cannot handle yet, so we know what to build next. |
route_to_tool | Which compressor a file was sent to from the home page. |
compress_complete | That compression finished, the format, and coarse size and duration bands. |
compress_error | That compression failed, and a short reason code. |
download_result | That a result was downloaded, and in what format. |
sample_loaded | That the sample file was used rather than one of your own. |
theme_toggle | That the light or dark theme was switched. |
outbound_click | That a link to another site was followed. |
Google Analytics also collects the standard information any analytics tag receives: your IP address, which it uses to derive an approximate location and then discards, your browser and device type, the page you are on and the site you arrived from. It sets cookies to recognise a returning browser. Google acts as our data processor for this, and its own privacy policy governs what it does with the data. Our measurement ID is G-8S65TEMB97, should you wish to block it specifically.
Opting out. Any content blocker or tracker blocker will stop the analytics tag loading, as will your browser's "do not track" or anti-tracking settings in most cases. The site is built so that every event call quietly does nothing when the tag is absent. Blocking analytics does not affect the compressors in any way: they run entirely on your device and do not consult analytics for anything.
Hosting and server logs
The site is served as static files by Cloudflare Pages. As with any web host, Cloudflare records standard request logs, which include IP addresses, for security and abuse prevention. These logs cover requests for the pages, styles, scripts and fonts that make up the site. They cannot contain your files, because your files are never requested from or sent to a server.
What we do not do
- No accounts, so there is nothing to sign up for and no profile to build.
- No advertising, and no advertising or marketing trackers.
- No selling or sharing of data with anyone beyond the processors named above.
- No email collection, and no newsletter.
- No watermarks, paywalls or daily limits that would require identifying you.
Children
This site is a general purpose utility and is not directed at children. We do not knowingly collect personal information from anyone, of any age, beyond the analytics described above.
Your rights
If you are in the UK or the EU, data protection law gives you rights over personal data held about you, including the right to access it, correct it, have it erased, and object to its processing. In practice we hold very little: we have no accounts and no database of users, so for most requests the only relevant data is the analytics record tied to your browser's cookie, which you can clear yourself at any time by clearing your cookies. If you want to exercise any of these rights formally, or complain about how we handle data, write to us at the registered address below. You also have the right to complain to the Information Commissioner's Office, the UK supervisory authority.
Changes
If this policy changes, the date at the top of the page changes with it. We do not keep a mailing list, so there is nobody to notify.
Who we are
nanofile.io is operated by Convert Case Ltd, the data controller for the purposes of this policy.
Registered in England and Wales. Company number: 11614495.
Registered office address: C4DI @TheDock, 31-38 Queen Street, Hull, England, HU1 1UU.