Fathym offers Free Trial, but Observable does not.
Observable is designed for Individuals, Medium Business and Small Business.
Fathym is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Observable Starts at $9/User/Month whereas for Fathym Starts at $12.50/Month when Billed Yearly.
Some top alternatives to Observable includes CodePen, Visualr, ibi Analytics Platform, Instadeq, Dashana, Ideata Analytics, Vizician, Zoomdata and Vizydrop.
Some top alternatives to Fathym includes Codeanywhere, AWS Cloud9, Visual Studio IDE, CodeinCloud, CodePen, CodeTogether, Clustered Cloud, iofod, CodeOnline and Serverless Cloud.