Goto plugin’s page on wordpress plugins directory, click on Advanced view (see below pic) and check below things before installing a WordPress plugin.
1. Check plugin version
On right side of the plugin’s advanced view page, plugin version appears. If the plugin shows Alpha or Beta version, it means it is still in development or is being tested. If you install such plugins it may affect your site.
If you can’t find alternative plugin, wait until that plugin is fully tested and released. Note that higher the version number,more mature (stable and tested) the plugin is .
2. Check popularity of the plugin
Check total number of downloads or active installations (refer 2nd pic) and it’s rating by users. More installations means that plugin is more popular, but check the ratings also. If the plugin has good rating (say 75 users gave 5 stars out of 100), that plugin has good success rate.
3. Check when the plugin was updated
If the plugin is not updated in several years, developer might have stopped support or it’s maintenance. In such cases, the plugin may affect your site when there are major WordPress updates. You can goto plugin’s home page -> Support tab and check for issues or fixes from users on the plugin’s forum.
4. Check number of downloads per day
On plugin’s advanced view page , you can see plugin stats like downloads per day, download history and active versions. This data indicates the success rate of the plugin. More downloads, more popular the plugin is.
5. Check “See what others are saying” section
Goto plugin’s home page -> Reviews tab. It displays all kind of comments and it is a good place to read users feedback on whether the plugin works well or not.