hugo server won't start: port already in use

You run hugo server and get:

Error: listen tcp 127.0.0.1:1313: bind: address already in use

Something is already listening on port 1313. Nine times out of ten it’s a hugo server you started earlier – in a terminal tab you closed without stopping it, or in another window.

The quick way out: use another port

hugo server --port 1314

That’s it. Nothing is broken; two servers just can’t share one port.

Find what’s holding the port

lsof -i :1313

COMMAND   PID  USER   FD   TYPE  DEVICE  SIZE/OFF  NODE NAME
hugo    47118 anders   9u  IPv4  0x...      0t0     TCP localhost:bmc-perf-agent (LISTEN)

If it’s a Hugo process you forgot about, stop it:

kill 47118

Stop every Hugo server at once:

pkill -f "hugo server"

If it isn’t Hugo, look at the COMMAND column before you kill anything – 1313 is Hugo’s default, but other tools use nearby ports.

It says the port is in use, but nothing is listening

Two cases worth knowing about:

• The old process is a zombie. lsof shows a Hugo PID, but the browser gets nothing. kill it and start again.
• You’re behind a different address. hugo server binds to 127.0.0.1 by default. Something bound to 0.0.0.0:1313 (a container, a VM) occupies the same port from your machine’s point of view.

Don’t fight the port – reuse the server

If the server that owns the port is already serving the site you’re working on, you don’t need a new one. Open http://localhost:1313/ and keep working; Hugo is already watching your files.

HugoKit gives every site its own port – it tests the port by actually binding it before offering it, so two sites can run side by side. It warns you before you start if the port is taken, and if Hugo does fail with address already in use, HugoKit looks for the server that’s already running on that port and attaches to it instead of starting a second one. See Running the server.