Most "free EML to PDF" sites are upload forms in disguise: your emails travel to someone else's server, get processed by unknown code, and you hope they are deleted. This tool is different in a way you can verify — the conversion is not just private by policy, it is private by architecture.
The entire pipeline — MIME parsing, PDF rendering, ZIP packaging — is JavaScript running in your browser tab. There is no upload endpoint because there is no server to receive one.
The site is a set of static files. When you open it, your browser fetches the code (once). From that moment the app is self-contained: the EML parser, the CJK-capable PDF typesetting engine and the ZIP writer all execute in your tab against local memory. No fetch() call touches your files.
This is why the tool is safe for the emails people are most afraid to upload: legal correspondence, medical records, HR investigations, client communications. Nothing can leak from a computer that never sent it.
Local conversion is not a licence claim about what your browser already has: if you install extensions with page access, or sync downloads to a cloud folder, that happens outside this tool. The guarantee is narrow and strong — this page sends your files nowhere — and you can audit it yourself in five minutes with the network panel.
No. There is no server-side component; conversion is pure client-side JavaScript. Once the page has loaded, you can go offline and keep converting in the open tab.
Because they run the conversion on their servers — which means your emails pass through, and often rest on, machines you do not control.
Nothing but the ZIP you downloaded. Emails and PDFs live in tab memory only — closing the tab clears them. (The browser's normal HTTP cache of the page code itself contains no email data. Note that reloading the page while offline may require a reconnect, since there is no offline app-cache in the current version.)