OpenAnyFile
What is a .p7m file?
PKCS#7 Signed Document (CAdES) is a certificate and key format developed by RSA Laboratories / IETF, first released in 1998. It is usually created by Italian e-invoicing (FatturaPA), PEC, smart-card signing.
The original file sits inside the signature envelope. OpenAnyFile extracts it locally so you can open the invoice or PDF — no smart card or signing software needed.
File details
| Full name | PKCS#7 Signed Document (CAdES) |
|---|---|
| Category | Certificates & keys |
| MIME type | application/pkcs7-mime |
| Signature (magic bytes) | 30 80 or 30 82 (ASN.1 SEQUENCE) or Base64 text |
| Developer | RSA Laboratories / IETF |
| Introduced | 1998 |
| Opens with | Signature and certificate decoder |
| Uploaded? | No — read locally in your browser |
How to open a .p7m file
OpenAnyFile routes .p7m files to its signature and certificate decoder, which shows the certificates, and any signed file inside ready to open.
- Drop your .p7m file on the box above, click it to choose the file, or paste it with Ctrl+V.
- The real format is detected from the file's first bytes — not just its name.
- The file opens in the signature and certificate decoder.
- Use fullscreen for a closer look, check its checksums, or download it back unchanged.
What works — and what does not
Works
Viewing and inspecting: the certificates, and any signed file inside ready to open. Size, type, signature and checksums are always shown.
Does not work
Editing and saving back. OpenAnyFile is a viewer, not an editor — for changes you still need the original app.
Is it safe to open a .p7m file online?
Here, yes — because nothing is uploaded. Most "online viewers" send your file to their server. OpenAnyFile reads it with your browser's File API and decodes it on your own device, so there is no copy anywhere else. You can check: open your browser's network tab while opening a file — no upload appears.
Questions about .p7m files
Can I open a .p7m file without installing software?
Yes. OpenAnyFile opens .p7m files in your browser using its signature and certificate decoder. You get the certificates, and any signed file inside ready to open, with nothing installed and no account.
How do I know a file is really a .p7m file?
Check its first bytes instead of its name. A genuine P7M file begins with 30 80 or 30 82 (ASN.1 SEQUENCE) or Base64 text. OpenAnyFile shows the detected type, so a renamed file is easy to spot.
Is my .p7m file uploaded anywhere?
No. The file is read locally by your browser and never sent to a server — it even works offline once the page has loaded.
Does it work on phones?
Yes — on Android and iPhone, in any modern browser. You can also install OpenAnyFile as an app.
Related formats
Other formats from the same family:
Format facts checked and page updated on September 25, 2026.