EADDRINUSE error: Sanity Studio won't start, port 3333 already in use
This is a classic port conflict error - the EADDRINUSE: address already in use 127.0.0.1:3333 message means something is already running on port 3333, which is where Sanity Studio is trying to start.
Here are a few ways to fix this:
1. Find and kill the process using port 3333:
On Mac/Linux:
lsof -ti:3333 | xargs kill -9Or find the process ID first to see what it is:
lsof -i:3333On Windows (Command Prompt):
netstat -ano | findstr :3333
taskkill /PID <PID_NUMBER> /F2. Use a different port:
You can start Sanity Studio on a different port by adding the --port flag:
sanity start --port 33343. Common causes:
- You might have another Sanity Studio instance already running in a different terminal/tab
- Your Gatsby dev server might be using that port
- A previous Studio process didn't shut down cleanly
- You have another development server configured to use port 3333
4. Nuclear option - restart your terminal/computer:
If you can't find the process, sometimes the easiest solution is to close all terminal windows and restart, or restart your computer entirely.
The most likely scenario is that you have another instance of sanity start already running somewhere. Check all your terminal windows/tabs first before killing processes!
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