Please pardon me if this is be a duplicate which I would be fain to delete. Please feel free to edit this post and tags.
I'm seeking a syntax checker (preferably free) for Latex and MathJax and etc, that allows TEX code to be copied and pasted directly thereinto. This checker shouldn't require code to be typed in another Latex program. If necessary, it could parse a saved PDF or Notepad or Word file in which I wrote the Tex code. Please let me know if this answers the question of "static program analysis"?
This program would then divulge and signalise all errors and problems.
Would the programs in Is there a program equivalent to lint for LaTeX? suit the above?