Everything runs on your machine — your input is processed right here in your browser and never uploaded to any server.
Paste your certificate and its CA chain (all the "BEGIN CERTIFICATE" blocks).
Click "Create .p7b".
Import the downloaded certificate.p7b into Windows/IIS or your Java keystore.
A .p7b (PKCS#7) file is a bundle of certificates — your domain certificate plus its chain — in the format Windows certificate stores, IIS, and Java keytools like to import in one go. This tool packs your PEM certificates into one, entirely in your browser.
P7B files never contain a private key — that is a property of the format, and a useful one: you can send a .p7b around freely. If you need the key included, you want a PFX instead; there is a dedicated PEM → PFX tool for that.
100% private“The bundle is assembled entirely in your browser and never uploaded. P7B files contain only public certificates — no private key is ever involved on this page.”
Completing a certificate request on Windows imports the CA’s response, and a .p7b carries the full chain in one file, letting Windows place each certificate in the right store automatically.
Never — the format cannot carry one. That makes it safe to email or publish. To bundle the key too (for moving a site between machines), create a .pfx instead.