ProtOSINT - Python script that helps you investigate Protonmail accounts and ProtonVPN IP addresses

ProtOSINT is a Python script that helps you investigate ProtonMail accounts and ProtonVPN IP addresses.

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This tool can help you in your OSINT investigation on Proton service (for educational purposes only).
ProtOSINT is separated into 3 sub-modules:

  • [1] Test the validity of one protonmail account
  • [2] Try to find if your target has a protonmail account by generating multiple addresses by combining information fields inputted
  • [3] Find if your IP is currently affiliate with ProtonVPN

⚠️ Important update of the ProtonMail API [2021-11-07] ⚠️

For several days, we observe an update in ProtonMail's API:

  • The API now seems to be limited to a few queries (ten/fifteen requests).
  • The blocking time is one hour (the limitation seems to be by IP address).
  • Even if an email is not valid, the API will return a result that seems valid with a random timestamp.
  • However, if the email is really valid, the timestamp returned is still good.

Advice for using ProtOSINT nowadays

  • Use only modules 1 and 3.
  • Before using module 1, first, test the validity of your email with a third party tool or with the recipient field directly in the ProtonMail web interface:

Then, using ProtOSINT, get additional information (the public key attached to the email, the date the PGP key was created and the encryption used).


Python 3




The account name in the protonmail is case-insensitive and ProtonMail considers the "." "_" "-" symbols as transparent. Additionally, any words put after a "+" sign are not taken into account. It means that all of these email addresses below are the same as [email protected]:

All of these emails have the save timestamp and refers to the account [email protected].

This technique does not always give you the creation time and date of the ProtonMail account itself, but the time and date when the email address itself was created (thanks to @sector035 for the tip:

Email encryption keys

ProtOSINT allows you to know which encryption key is used for a protonmail account:

  • RSA 2048-bit (Older but faster) - high security
  • RSA 4096-bit (Secure but slow) - highest security
  • X25519 (Modern, fastest, secure) - State-of-the-art


Feel free to clone this project. For major changes, please open an issue first to discuss what you would like to change.

January 13, 2022
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