Closest thing I know of is https://github.com/kristoff-it/superhtml#diagnostics https://github.com/kristoff-it/superhtml#diagnostics SuperHTML validates not

Closest thing I know of is https://github.com/kristoff-it/superhtml#diagnostics https://github.com/kristoff-it/superhtml#diagnostics SuperHTML validates not only syntax but also element nesting and attribute values. No other language server implements the full HTML spec in its validation code.