Every step below is from an official source
Switch from Bitwarden to Apple Passwords (iCloud Keychain)
What to do at Bitwarden before you leave, what Apple Passwords (iCloud Keychain) 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 Bitwarden, before you leave
Export from the Bitwarden web appBefore
In the web app, select Tools, then Export, and choose what to export. Pick .json, .csv, encrypted .json, or .zip with attachments, then confirm with your master password or an email code.
Export vault dataBitwarden Help Center. ReviewedKnow what Bitwarden exports leave outBefore
No export format includes trash items or Sends. Individual vault exports do not include items owned by an organization.
Export vault dataBitwarden Help Center. ReviewedUse .json to keep cards, identities and passkeysBefore
Only .json exports include cards, identities, stored passkeys and SSH keys.
Export vault dataBitwarden Help Center. ReviewedProtect and delete an unencrypted exportAfter
Unless the export is encrypted, don't store or send it over insecure channels like email. Delete the file right after use.
Export vault dataBitwarden Help Center. Reviewed
At Apple Passwords (iCloud Keychain), when you join
Import a CSV file into Passwords on MacDuring
Export your passwords from your old app as a CSV file. In the Passwords app, choose File > Import Passwords from File, choose the file, then click Import.
Import passwords from another app into Passwords on MacApple. ReviewedReview passwords that didn't importAfter
Imported passwords won't replace ones already in the Passwords app. You can review any passwords that couldn't be imported.
Import passwords from another app into Passwords on MacApple. ReviewedDelete the CSV file after importingAfter
When the import finishes, Apple's steps have you delete the CSV file to protect your accounts.
Import passwords from another app into Passwords on MacApple. Reviewed
Then: everything else the switch affects
The steps above are what Bitwarden and Apple Passwords (iCloud Keychain) 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.