conda activate

Activate a conda environment

Overview

The conda activate command activates a conda environment by modifying your shell’s PATH and environment variables. This is a sourced command that must be run in your shell, not as a standalone executable.

Before using conda activate, you must initialize conda for your shell using conda init. This sets up the necessary shell integration.

Syntax

conda activate [environment_name_or_path]

If no environment is specified, activates the base environment.

Arguments

environment_name_or_path · string

Name of the environment to activate, or full path to the environment prefix. If the argument contains / or \, it’s treated as a path; otherwise, it’s treated as an environment name.

If not specified, the default activation environment (usually base) is activated.

Options

--stack · boolean

Stack the new environment on top of the current environment rather than replacing it. This allows you to have multiple environments active simultaneously.

When stacking:

• The new environment’s PATH is prepended
• The current environment remains accessible
• Use conda deactivate multiple times to unstack

--no-stack · boolean

Do not stack the environment (default behavior). This replaces the current active environment with the new one.

--dev · boolean

Use sys.executable -m conda in wrapper scripts instead of CONDA_EXE. This is mainly for development and testing purposes.

What Happens During Activation

When you activate an environment, conda performs several operations:

1. Update PATH

   Prepends the environment’s bin/ (or Scripts/ on Windows) directory to your PATH, making the environment’s executables available.

2. Set environment variables

   Sets conda-specific environment variables:

   • CONDA_PREFIX: Path to the active environment
   • CONDA_DEFAULT_ENV: Name of the active environment
   • CONDA_SHLVL: Shell level (increments with each activation)
   • CONDA_PROMPT_MODIFIER: Prompt modifier string
3. Run activation scripts

   Executes any activation scripts located in $CONDA_PREFIX/etc/conda/activate.d/. These scripts can set additional environment variables or perform setup tasks.

4. Update command prompt

   Modifies your shell prompt to show the active environment name (if changeps1 is enabled in config).

Environment Variables Set

Variable	Description
CONDA_PREFIX	Full path to the activated environment
CONDA_DEFAULT_ENV	Name of the environment (or “base” for base environment)
CONDA_SHLVL	Shell level - number of active environments (0 = no active environment)
CONDA_PROMPT_MODIFIER	String to prepend to shell prompt
CONDA_PREFIX_N	When stacking, stores previous environment paths (N = shell level)
CONDA_STACKED_N	Indicates if environment at level N was stacked

Examples

Activate an environment by name

conda activate myenv

Activates the environment named myenv from the default envs directory.

Activate an environment by path

conda activate /path/to/my/env

Activates an environment at a specific location.

Activate the base environment

conda activate

or explicitly:

conda activate base

Stack environments

conda activate base
conda activate --stack myenv

Now both base and myenv are active, with myenv’s PATH taking precedence.

Reactivate current environment

If you’re already in an environment and run conda activate on the same environment, conda will reactivate it (refresh environment variables and run activation scripts).

conda activate myenv  # First activation
conda activate myenv  # Reactivates the same environment

Shell Support

Conda activation works with multiple shells:

• Bash - Linux, macOS, Windows (Git Bash, WSL)
• Zsh - macOS, Linux
• Fish - Linux, macOS
• PowerShell - Windows, cross-platform
• Cmd.exe - Windows
• Tcsh/Csh - Linux, macOS
• Xonsh - Cross-platform

Common Use Cases

Switch between project environments

Quickly switch between different project environments:

conda activate project1
# Work on project1
conda deactivate

conda activate project2
# Work on project2

Automatic activation in scripts

Activate environments in shell scripts:

#!/bin/bash
eval "$(conda shell.bash hook)"
conda activate myenv
python script.py

Stacked environments for testing

Stack a testing environment on top of your base environment:

conda activate base
conda activate --stack test-env
pytest
conda deactivate  # Returns to base

Development with multiple tools

Use stacking when you need tools from multiple environments:

conda activate base-tools
conda activate --stack project-env
# Now you have access to tools from both environments

Troubleshooting

CommandNotFoundError: conda activate

If you get this error, you need to initialize conda for your shell:

conda init bash  # or zsh, fish, etc.

Then restart your shell or run:

source ~/.bashrc  # or ~/.zshrc, etc.

Environment not found

If conda can’t find your environment:

1. List all environments: conda env list
2. Use the full path: conda activate /full/path/to/env
3. Check if the environment exists in your envs directory

PATH not updated correctly

If your PATH isn’t updated after activation:

1. Check that conda is properly initialized
2. Try reactivating: conda deactivate && conda activate myenv
3. Verify with: echo $PATH

Related Commands

• conda deactivate - Deactivate the current environment
• conda env list - List all available environments
• conda create - Create a new environment
• conda info - Display information about current environment