keychain2bitwarden

keychain2bitwarden is a js utility to convert a macOS Safari Keychain export csv to Bitwarden's json format.

Usage

Export your Keychain passwords via Safari on MacOS:
Preferences → Passwords → … → Export passwords.
Save the csv file in a convenient place.
Run keychain2bitwarden convert on that export file:

npx keychain2bitwarden convert Passwords.csv > keychain.json

Note that keychain2bitwarden outputs to stdout, so you'll need to redirect it's output to your file.

Import keychain.json in your Bitwarden vault through the web UI at https://vault.bitwarden.com/#/tools/import
Delete both Passwords.csv as keychain.csv — as these files contain all your passwords in plain text, so don't leave these laying around!