Contact

Everything comes to one address — hello@zellio.io — and a word in the subject line routes it. Every message is read; bug reports and security reports get priority.

Bug reports

Subject: Bug. The three details that turn a vague report into a fixable one: which tool you were using, what you did and what happened instead, and your browser and device. If the problem involves a specific input, describe its shape — "a 40 MB PNG" or "a CSV with semicolons" — rather than sending the file itself, especially if it is private. We cannot see your data, which is the point of the site, so your description is all we have to go on.

Tool requests

Subject: Request. The most useful request describes the task, not the feature: "I keep needing to do X and end up doing Y instead" tells us far more than a tool name. Requests that fit the site's one rule — your data never leaves your device — have a good record of getting built.

Security reports

Subject: Security. See the security page for what is in scope and how reports are handled. Genuine findings are acted on promptly and credited in the changelog if you want the credit.

Privacy questions

Subject: Privacy. The short version is in the privacy policy; if something there is unclear or seems inconsistent with what the site does, that specifically is worth an email — the policy is meant to match the behaviour exactly.

Anything else

Feedback, corrections to a guide, a factual error on a tool page, business enquiries — same address. If you spot a mistake in something we have written, please say so plainly; the content is maintained and corrections genuinely land.

Because Zellio.io runs entirely in your browser, we cannot access your files or data — so please don't send sensitive information by email.