Short answers — see the Docs page for the longer version of how anything here actually works.
No. It's a display tool for certificates you already have, not a verification service — see the Content Policy for what that does and doesn't mean.
Whoever you let. Each certificate is Public (on your wall, to anyone), Unlisted (only reachable with the exact link), or Private (only you). Independently, your whole wall can be turned off (invisible to everyone but you) or PIN/password-protected in Settings → Privacy.
Yes — draw boxes over the parts you don't want shown (a signature, an ID number, an address) and redact. The covered regions are permanently blacked out of a new file; nobody but you ever sees the original again unless you remove the redaction.
It doesn't hide the certificate — it still opens inline for anyone who can already see it. It only removes the explicit, save-to-disk download link for non-owners, who see a watermarked preview instead.
PDF or image (JPEG/PNG/WebP), up to 5MB. Every file is validated by its actual content, re-encoded, and best-effort virus-scanned before it's stored — not just checked by filename.
A revoked link stops working immediately for anyone who has it. Deleting the certificate does the same, permanently, along with the original file, its thumbnail, and any redacted copy.
Not for 90 days. A freed username is frozen for that long (nobody, including you, can claim it) so it can't be picked up by someone else to impersonate you right after you stop using it.
Everything is removed permanently — your wall, every certificate, and all their files. Your username is frozen for 90 days afterward, same as changing it. This can't be undone.
No. The admin-visible analytics in this app are built entirely from its own database — anonymized visit/view counts only, never per-visitor identity — and no third-party advertising or analytics service is integrated anywhere.
Most of them. A few of the newer, more elaborate frame styles are shown as a preview of what's coming with a future paid tier but aren't selectable yet — everything else, including AI-assisted title/description suggestions (free-tier provider), is free.
Every certificate page has a Report link. Enough reports on the same certificate within a day automatically holds it from public view pending review — it's never deleted outright by this process.
Yes — generate a key from Settings → API access and see the API docs for authentication, endpoints, and rate limits.
Not currently — the site itself is fully responsive and works well on a phone's browser.