Privacy Policy
Effective date: August 12, 2026 — this revision adds the controller, lawful basis and data-subject rights sections. Nothing about what the site collects changed, because it still collects nothing.
Your files never leave your device
Every repair CSVUndo performs — converting scientific notation back to full numbers, restoring leading zeros, fixing broken characters — runs entirely inside your browser using JavaScript. When you choose a file, your browser reads it into memory, processes it locally, and hands the corrected version back to you as a download. The contents of your file are never transmitted to our servers or to anyone else's. There is no upload code on this site, so we could not read your data even if we wanted to. When you close the tab, the file is gone from memory.
You can verify this yourself: open your browser's developer tools, switch to the Network tab, and repair a file. You will see the page and its assets load, and nothing else — no request carries your data out. The proof page walks through that check, plus the airplane-mode test and the security header that enforces it.
No accounts, no cookies from us
CSVUndo has no signup, no login, and no user profiles. We do not set cookies, and we do not run analytics scripts that identify or track you across other sites. There is nothing to unsubscribe from because we never asked for your email in the first place.
Advertising
There is no advertising on this site, and nothing here loads from an ad network. The script-src 'self' in our Content-Security-Policy blocks third-party scripts outright, so an ad tag could not run even if one were added to the markup by mistake.
If that ever changes we will say so here first, and it would be a real change rather than a switch we flip: the security policy would have to be widened in three separate files, and the personalised-advertising cookies an ad network sets would need your consent before they were set, not after. Whatever happens to advertising, it cannot reach the files you repair — those are never sent anywhere in the first place.
Server logs
Like virtually every website, our hosting provider keeps standard access logs. These record the IP address, browser user agent, requested page, and timestamp of each visit. We use them only to keep the site secure and running — spotting abusive traffic, diagnosing outages, and blocking attacks. They never contain the contents of your files, because your files are never sent to the server.
Those logs are created and held by the host on its own retention schedule, not copied anywhere by us. We do not export them, combine them with anything else, or use them to build a profile of anyone — so the period they exist for is whatever our hosting provider applies to its standard access logs, and we neither extend it nor keep a copy after it. If you want the current figure for your own records, ask us and we will get it from the host.
Who is responsible, and your rights
CSVUndo is published and operated by one individual, who is the data controller for the small amount of personal data described above and is reachable at [email protected] or through the contact page. Ask there for the operator's full legal name and postal address and we will give them to you.
The lawful basis for processing the access logs is legitimate interests — keeping the site available and defending it against abuse. Those logs are the only personal data connected with this site: there are no accounts, no cookies, no analytics, no advertising, and the contents of your files are never received in the first place.
You have the right to ask what we hold about you, to have it corrected or erased, to object to the processing, to restrict it, and to complain to your local data-protection supervisory authority. In practice there is very little to give you, and that is the design rather than an accident — with no account, no identifier and no file contents, there is usually nothing that can be tied back to you at all.
Our hosting provider, Cloudflare, acts as a processor for the access logs and may serve this site from data centres outside your own country under its own standard data-protection terms.
What we will never do
- Sell, rent, or trade any information about you to anyone.
- Upload, inspect, store, or retain the CSV files you repair.
- Require personal information of any kind to use the tools.
Changes to this policy
If the way the site works ever changes — for example, if we add an optional feature that requires a server — we will update this page and move the effective date at the top. Material changes will be noted plainly, not buried.
Questions
If anything here is unclear, or you would like more detail about how the repairs work, reach us through the contact page. We answer.