Every step below is from an official source
Switch from Proton Pass to LastPass
What to do at Proton Pass before you leave, what LastPass needs when you join, and everything else the switch touches. Your full plan is built in your browser and stays there.
Official sources reviewed . How we review sources
At Proton Pass, before you leave
Export from Proton Pass settingsBefore
In the browser extension, web app or Windows app, open settings with the gear icon, then click the Export tab.
How to export from Proton PassProton Support. ReviewedUse a computer, not the mobile appBefore
You can't export data from the Proton Pass mobile apps.
How to export from Proton PassProton Support. ReviewedEncrypt the export if you store or send itDuring
You can export a ZIP with a PGP-encrypted JSON file, an unencrypted ZIP, or a CSV file. Proton recommends encrypting the file if you will keep it as a backup or transfer it.
How to export from Proton PassProton Support. Reviewed
At LastPass, when you join
Use a generic CSV if your manager isn't supportedBefore
If LastPass's on-screen import steps don't support your current password manager, you may be able to import a generic CSV file. Check first that your current manager can export to CSV.
How do I import stored data into LastPass using a generic CSV file?LastPass. ReviewedMatch your CSV columns to the LastPass templateDuring
Column titles must match LastPass's sample template. The columns are url, username, password, extra, name, grouping, fav and totp.
How do I import stored data into LastPass using a generic CSV file?LastPass. ReviewedUse passive import if your manager can't exportDuring
Run LastPass alongside your old password manager. Visit each site, let the old manager fill in your login, then add it to LastPass.
Then: everything else the switch affects
The steps above are what Proton Pass and LastPass say. Your full checklist adds the accounts, codes, payments and devices that depend on your password manager, in a safe order. It's built from your answers, in your browser.