Barnsdall.org W3C HTML Markup Validation
HTML markup errors and warnings
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Errors:
A document must not include both a “meta” element with an “http-equiv” attribute whose value is “content-type”, and a “meta” element with a “charset” attribute.
Bad value “https://api.w.org/” for attribute “rel” on element “link”: The string “https://api.w.org/” is not a registered keyword.
Element “img” is missing required attribute “src”.
An “img” element must have an “alt” attribute, except under certain conditions. For details, consult guidance on providing text alternatives for images.
No space between attributes.
Quote “"” in attribute name. Probable cause: Matching quote missing somewhere earlier.
Bad value for attribute “href” on element “a”: Illegal character in query: space is not allowed.
Attribute “sidebarbutton"” not allowed on element “a” at this point.
Element “style” not allowed as child of element “aside” in this context. (Suppressing further errors from this subtree.)
No “p” element in scope but a “p” end tag seen.
Warnings:
Consider avoiding viewport values that prevent users from resizing documents.
Attribute “sidebarbutton"” is not serializable as XML 1.0.
Article lacks heading. Consider using “h2”-“h6” elements to add identifying headings to all articles.
Section lacks heading. Consider using “h2”-“h6” elements to add identifying headings to all sections.
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