Use the ACE HTML Block to get some assistance when writing HTML.

Screenshot

Example

Ace HTML block

It’s a block that syntax highlights HTML as you type it.

Bad HTML – no end tag

Notes

• The ACE HTML Block plugin appears to use the same editor that Gutenberg tried to use for Custom HTML – core/html.
• If you write invalid HTML then the block may display `This block contains unexpected or invalid conent.` on the next edit. Choose More Options Attempt Block Recovery.
• Transforms to Custom HTML – core/html, Group – core/group, Shortcode – core/shortcode.
• It may lose the content during the transformation.
• A Custom HTML block can be transformed to an ACE HTML block.