Note: Most Altium files are saved in the native format .intLib. However, you may occasionally run into cases where they're saved as .lia. After unzipping the file, check the extension of the file you downloaded and follow the relevant instructions below.
For Native format (.intlib):
Follow these steps to import symbols & footprints into Altium Designer using the .intlib format:
Double-click the downloaded .intlib file or drag & drop the downloaded .intlib file to the Altium window.
A pop-up window will appear. You have a choice to Extract Sources or Install Library.
Extract Sources will allow you to open the library into the Projects window as an Integrated Library project.
Install Library will install the library and add it to your Libraries Panel.
For P-CAD format (.lia):
**Before import, make sure the P-CAD importer is installed. To do so, follow these instructions here.**
Follow these steps to import symbols & footprints into Altium Designer using the .lia file.
Drag the .lia file into Altium. This will invoke the P-CAD Import Wizard.
Click Next until you reach the Current Layer Mapping window.
If present, map the layers as follows:
For Layer '10', choose: Mechanical Layer 1
For Layer '20', choose: Mechanical Layer 13
For Layer '21', choose: Mechanical Layer 15
Follow the remaining prompts to complete the import
Some other benefits of this plugin:
The ability to add models to your library folder for future use
Native .SchLib and .PcbLib libraries
3D models embedded inside the footprints
SnapEDA Desktop App
And finally, you can also use the SnapEDA Desktop App, which will allow you to place parts seamlessly from your Desktop into your CAD tools in a Snap.
To get started, download the app here. To learn how to import into Altium using the Desktop App, read this article.