mozilla web console for html + javascipt both

[hisoka]

I looked for a tool  inside mozilla - by clicking Menu then developer -  in which I can write a code composed of both javascript and html . Unfortunately , I could not find in the developer any tool that accepts both html and javascript together . web console and scratchpad do not accept html . Is there  - may be - a tool inside Mozilla firefox or an extension that I overlooked and that could help me write a code of both html and javascript because I do not want to download a javascript developer tool from google

[Ingolme]

You can write HTML and Javascript in any text editor.

[hisoka]

it is a good idea but in a text editor , I do not see my errors  when I run the code in the browser because they are not shown like in scratchpad or web console . if there is an error I got only a blank page .  that , of course , makes it  very hard - at least for a beginner like me-  to notice my errors and therefore correct them . Moreover I need , every time , to save my code  as HTML and then launch it in the browser . No good thing

Edited August 15, 2017 by hisoka