If your terminal is slow to open, you can profile zsh startup to identify what’s causing the delay and optimize your configuration.

Quick timing check:

time zsh -i -c exit

This creates a temporary zsh subshell and shows total startup time.

Detailed profiling:

Add these lines to your ~/.zshrc:

# At the top of the file
zmodload zsh/zprof

# ... rest of your config ...

# At the bottom of the file
zprof

The built-in profiler will output timing data showing “num calls, time, self, and name” for each function, revealing which processes are slowest.

Common culprits:

Package managers often cause startup delays:

• nvm (Node Version Manager)
• pyenv (Python version management)
• conda (Python environment management)

Example:

One developer found that conda initialization was responsible for 4+ seconds of a 4.6-second startup time. Commenting out the conda block reduced startup to ~1 second.

Fix slow startup:

1. Run zprof to identify slow processes
2. Disable or lazy-load unnecessary initialization code
3. Consider using alternatives like zsh-defer for non-critical plugins
4. Remove tools you don’t actively use

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