Internships.com is definitely a good online tool for finding paid or unpaid internships.
InternQueen - It has everything you need to know about internships covered! You can search for opportunities depending on your preferred industry and semester, with the added option of virtual internship.
You also have a lot to learn from its blog, which offers awesome and engaging content on writing a resume, acing interviews, and other tips on successfully running a professional life!
Idealist – This is one of the popular online platforms for job seekers in the social sector. It connects any idealist with more than 100,000 organizations and resources for volunteer and open internships to transform their good intentions into actions.
CoolWorks.com - The website promises finding you a job at great places, which include national parks, ski resorts, conservation centers, summer camps, and retreat centers. Great place where you can find an internship that strikes a balance between work and fun, especially since they believe that you can and should love your job.
Looksharp.com – This site has a wide offering of over 30,000 internship openings for students and fresh graduates that can be looked up through college major, keywords or location. Top and featured companies include Facebook, UPS, and Northwestern Mutual. Definitely worth looking into!