Windows

Download the latest version of Lidarr from https://lidarr.audio

Extract the zip file into your target directory. Use a folder that Lidarr process would have write access to (DO NOT use C:\Program Files or C:\Program Files (x86))
Run Lidarr.exe once as administrator to register the port and URL with Windows (Required for remote access)¹
Manually start Lidarr by running Lidarr.exe or ServiceInstall.exe to install Lidarr as a Windows service.
Open http://localhost:8686 in your browser

¹ The port will be opened on the firewall (if enabled) for the private profile only, if you're connected to a domain or a public network the port will not be opened automatically, but can be done so manually.

macOS

Manually

Download latest version of Lidarr's OSX package from https://github.com/lidarr/Lidarr/releases
Open the archive and drag the Lidarr icon to your Application folder.
- Note: In macOS 10.12+ Gatekeeper App Translocation will prevent Lidarr run directly from the Downloads folder from updating
Open Lidarr.app
You should now be able to access Lidarr at http://localhost:8686

Docker

Docker is available on Linux, macOS and Windows

Full instructions: https://github.com/lidarr/Lidarr/wiki/Docker

Running Lidarr in a Docker container eases setup and reduces package installation on the host OS. Docker is available on many platforms see the Docker overview page and install Docker before setting up a Lidarr under Docker. Once Docker is installed you'll need to pull the image with docker pull hotio/lidarr or docker pull linuxserver/lidarr and then create the container. See https://hub.docker.com/r/hotio/lidarr/ or https://hub.docker.com/r/linuxserver/lidarr/ for the options available when creating the image.

Linux

- Mono 5.8 or later is required :

Download and install mono here

https://www.mono-project.com/download/stable/

- Install Lidarr :

Get to directory /opt

cd /opt

Download Lidar.tar.gz: https://github.com/lidarr/Lidarr/releases <--- Download latest version here

sudo wget https://github.com/lidarr/Lidarr/releases/download/v0.6.2.883/Lidarr.develop.0.6.2.883.linux.tar.gz

Extract package

sudo tar -xzvf Lidarr.*.linux.tar.gz

Try to run in shell - /!\ not permanently /!\

sudo mono --debug /opt/Lidarr/Lidarr.exe

Lidarr should be available on port 8686, for example: http://localhost:8686

Autostart, permanently, follow next step

Create Lidarr user and group, eg:

useradd -s /bin/false -d /var/lib/lidarr/ -r -m -U lidarr

Change owner and permissions for lidarr application files:

chown -R lidarr:lidarr   /opt/Lidarr
chmod -R a=,a+X,u+rw,g+r /opt/Lidarr

Run lidarr as system service: Autostart on Linux
Lidarr should be available on port 8686, for example: http://localhost:8686