Every step below is from an official source
Switch from Apple Passwords (iCloud Keychain) to Bitwarden
What to do at Apple Passwords (iCloud Keychain) before you leave, what Bitwarden 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 Apple Passwords (iCloud Keychain), before you leave
Export all passwords to a CSV file on MacBefore
In the Passwords app on your Mac, choose File > Export All Passwords to File, click Export Passwords, then choose where to save it.
Export passwords from your Mac to a fileApple. ReviewedKnow which passwords can't be exportedBefore
You can't export Wi-Fi passwords, passwords shared with a group you didn't create, or access to Sign in with Apple accounts.
Export passwords from your Mac to a fileApple. ReviewedTreat the exported file as unprotectedDuring
Exported passwords are not encrypted. Anyone who can open the file can see them.
Export passwords from your Mac to a fileApple. ReviewedDelete the file after importing elsewhereAfter
Once the passwords are in your new password manager, delete the file you exported.
Export passwords from your Mac to a fileApple. Reviewed
At Bitwarden, when you join
Import from LastPass, 1Password, Chrome and moreDuring
Bitwarden supports imports from common password managers, including LastPass, 1Password, Firefox, Chrome, Edge, Chromium, Password Safe and other Bitwarden vaults.
Import to your vault or collectionsBitwarden Help Center. ReviewedImport LastPass directly, then add attachments by handDuring
Bitwarden's browser extensions and desktop apps can import your individual LastPass vault directly, with no file upload. File attachments and trash must be uploaded to your vault by hand.
Import from LastPassBitwarden. ReviewedSplit files with more than 40,000 itemsBefore
An imported file can contain up to 40,000 items. If your file is too large, split it into smaller files and import each one.
Import to your vault or collectionsBitwarden Help Center. ReviewedDelete the export file after importingAfter
Once your data is in Bitwarden, delete the exported data file from your computer.
Import to your vault or collectionsBitwarden Help Center. Reviewed
Then: everything else the switch affects
The steps above are what Apple Passwords (iCloud Keychain) and Bitwarden 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.