Iconduck is a website that allows you to download over 100,000 icons for absolutely free. Almost all icons on Iconduck are under the MIT license, so feel free to use them in commercial as well as personal projects.
Iconduck There are no account constraints, and opening and searching is not as slow as some websites. On the Iconduck home page, enter the subject keyword of the symbol you want to find in the search box above.
In the results page browse for the icon and, if you like, tap> Download to download to your computer. The download icon is in SVG format and can be opened in a browser. The size of each icon is small and the size is quite large, not like the thumbnail on the website.
Iconduck has API support to do icon search on website / personal blog. You contact the site so they provide the API.