Neither Observable nor Replit offers a free trial.
Observable is designed for Individuals, Medium Business and Small Business.
Replit is designed for Individuals, Large Enterprises, Medium Business and Small Business.
Pricing for Observable Starts at $9/User/Month whereas for Replit Starts at $7/Month.
Some top alternatives to Observable includes CodePen, Visualr, ibi Analytics Platform, Instadeq, Dashana, Ideata Analytics, Vizician, Zoomdata and Vizydrop.
Some top alternatives to Replit includes Codeanywhere, ShiftEdit, Visual Studio IDE, CodePen, Repl.it, CodeTogether, CodeSandbox, Codefile, Anyfiddle and Interview Sandbox.