Powerlevel9k compatibility

Powerlevel10k understands all Powerlevel9k configuration parameters.

Migration from Powerlevel9k to Powerlevel10k is a straightforward process. All your POWERLEVEL9K configuration parameters will still work. Prompt will look the same as before (almost) but it will be much faster (certainly).

FAQ:

• I'm using Powerlevel9k with Oh My Zsh. How do I migrate?
• Does Powerlevel10k always render exactly the same prompt as Powerlevel9k given the same config?
• What is the relationship between Powerlevel9k and Powerlevel10k?