Tag Options

Check element nesting - Check this box if you want HTML Validator to report potential nesting problems from markup like <h1>HTML Validator <i>Released!</h1></i>. Here, the "h1" end tag appears before the "i" end tag, but the "i" end tag should appear first. This results in a nesting error. This option is enabled by default.

Treat elements as if they are always in a valid location - Check this box to override location (range) checking of elements. As long as an element's category is active, then the element will always be considered to be in a valid location regardless of the element's valid and invalid range settings. It is strongly recommended that you keep this option unchecked unless you have a good reason to enable it. This option is not enabled by default.

Tags with (first tag) can be anywhere - Check this box if you want any tags with (first tag) as the valid range to be valid anywhere. Otherwise if (first tag) is the only valid range for the tag, then it must be the first tag in the document (normally the first tag in a document should be the "html" tag). This option is not enabled by default.

Allow spaces immediately before the '>' character as in <span > or <p > - Check this box to allow spaces immediately before the closing '>' character in a tag. With this option checked, tags such as <b > will not generate warnings due to the spaces in the tags. We recommended that you leave this option unchecked for good style and to avoid possible problems caused by these spaces. Spaces immediately after the opening '<' character of a tag will generate an error message regardless of this setting. This option is enabled by default.

Allow empty-element tags - Check this box if you want HTML Validator to understand empty-element tags like <br /> and <img src="picture.gif" />. HTML Validator will also make sure that any empty-element tags do not have end tags. NOTE: Using empty-element tags for elements that are not void and not foreign content in HTML/HTML5 documents may still generate an error if this option is checked. This option is enabled by default.

For HTML (not XHTML) documents, require empty element syntax (<br />) if no end tag - Check this box if you want to generate error messages for tags in non-XML type documents (such as HTML) that do not have an end tag (like </tagname>) and are not already in the empty element form (<tagname ... />). For XML type documents (such as XHTML) this option is automatically enabled. This option is not enabled by default.

Warn if no space before '/' character for empty-element tags (good for backward compatibility) - Check this box to generate a warning message when there is no space before the trailing '/' and '>' of empty elements. In the past it was a good idea to include these spaces in XHTML documents for backward compatibility with HTML and older browsers (see https://www.w3.org/TR/xhtml1/#C_2), but now it is more a matter of style than practicality. With this option checked, using <br/> would generate a warning while <br /> would not. This option is not enabled by default.

Require optional end tags - Check this box if you want to require that all tags having optional end tags instead have required end tags. For example, <p> has an optional end tag if this option is unchecked. If this option is checked, then errors will be generated if there is not a matching </p> end tag for each <p> start tag. This may be useful for writing better HTML that is more like XHTML, for educational purposes, or for anyone whose style is to close all tags. This option is not enabled by default.

Change <% ... %> in &tags to '!ASP!' - Check this box to replace/change any <% ... %> block occurring in a tag to '!ASP!'. This minimizes the number of errors HTML Validator generates due to using <% ... %> blocks in tags. This option has no effect if Ignore text in <% ... %> (in the Miscellaneous Page) is not checked. NOTE: Similar processing is always done for PHP blocks and Miva macros. This option has no effect if HTTP header data is available, because it is assumed that the HTTP server has processed any scripting (New v10.00133). This option is enabled by default.

Ignore unknown tags in asp:* - Check this box to ignore unknown/unrecognized tags that are contained in an "asp:*" element like "asp:Label" (or, in v15.03+, a "telerik:*" element as well). This is useful for ASP.NET development. In v15.03+ this option also suppresses the message about an undeclared namespace prefix "asp" or "telerik" if the document wasn't requested via HTTP/HTTPS. This option is enabled by default. (New v8.00)

Ignore tags with colons in their names - Check this box so that tag names with a colon in them are ignored (such as "jsp:useBean"). This will also ignore all attributes and attribute values for that tag. This option will not ignore end tags with a colon but an end tag with a colon for a previously ignored start tag with a colon is OK. This option will not ignore tag names that are included in the configuration. This option is enabled by default.

Enable custom element support - Check this box to enable support for HTML 5.3 custom elements. If you are not checking any documents with custom elements then you may want to uncheck this option. This option is enabled by default. (New v18.0200)