PlantUML online rendering service can render a PlantUML file change in real time.
PlantUML Gist is real time rendering solution for plantUML file. We can play with plantUML. Add the string to plantUML rendering service URL: github/legenddcr/plantUML/blob/master/plantuml_gist.puml.
For example, to render this gist https://gist.github.com/legenddcr/fc33b3948e428d3ac1dd9f817022624b, you can append gist ID gist/fc33b3948e428d3ac1dd9f817022624b to PlantUML rendering service URL directly. For example use puml.alibaba.net: http://puml.alibaba.net/gist/fc33b3948e428d3ac1dd9f817022624b