GitHub offers Free Trial, but MERNKit does not.
MERNKit is designed for Individuals, Medium Business and Small Business.
GitHub is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for MERNKit Starts at $9.99/Month whereas for GitHub Starts at $4/User/Month.
Some top alternatives to MERNKit includes FusionAuth, GitHub, Gravity, 8base, SashiDo, Kodingless, Altogic, Serverless Cloud, SaaS Forge and AppSeed.
Some top alternatives to GitHub includes LiveCode, Codeanywhere, Visual Studio IDE, CodeinCloud, GitLive, Microsoft Azure, GitLab, CodeSee and Bitbucket.