Bad value “X aria-required=” for attribute “maxlength” on element “input”: Expected a digit but saw “ ” instead.

When you write an attribute like maxlength="200 and accidentally omit the closing quote, everything that follows — including subsequent attribute names and their values — gets absorbed into that one attribute’s value. In this case, the validator sees the value of maxlength as 200 aria-required= (or similar), which is not a valid integer. The parser doesn’t encounter a closing " until it finds the next quotation mark further along in the tag, causing a cascade of errors.

This is a problem for several reasons:

• Broken functionality: The maxlength attribute won’t work because 200 aria-required= is not a valid number. The browser cannot determine the intended character limit.
• Lost attributes: The aria-required attribute is swallowed into the malformed maxlength value, so it never gets applied as a separate attribute. Assistive technologies like screen readers won’t know the field is required.
• Accessibility impact: Since aria-required="true" is lost, users who rely on screen readers won’t receive the information that the field is mandatory, potentially leading to form submission errors and a frustrating experience.

The root cause is almost always a missing closing quotation mark. Carefully check that every attribute value has both an opening and a closing ". This kind of typo is easy to make and easy to miss, especially in long tags with many attributes.

Examples

Incorrect — missing closing quote on maxlength

The closing " after 200 is missing, so the value of maxlength extends all the way to the next quotation mark it finds:

<input type="text" name="nome" id="nome" maxlength="200 aria-required="true">

The validator interprets maxlength as having the value 200 aria-required=, and only true ends up as the value of an unintended or malformed attribute. Nothing works as expected.

Correct — properly quoted attributes

Each attribute has its own properly matched pair of quotation marks:

<input type="text" name="nome" id="nome" maxlength="200" aria-required="true">

Here, maxlength="200" correctly limits the input to 200 characters, and aria-required="true" is a separate attribute that tells assistive technologies the field is required.

Incorrect — missing closing quote with more attributes

This issue can happen with any combination of attributes. Here, a missing quote after maxlength absorbs class and placeholder:

<input type="text" maxlength="50 class="username" placeholder="Enter name">

Correct — all quotes properly closed

<input type="text" maxlength="50" class="username" placeholder="Enter name">

Tips for avoiding this issue

• Use a code editor with syntax highlighting. Most editors color attribute values differently from attribute names. If you see an attribute name rendered in the same color as a value string, a quote is likely missing.
• Format attributes one per line on complex elements. This makes it much easier to spot mismatched quotes:

<input
  type="text"
  name="nome"
  id="nome"
  maxlength="200"
  aria-required="true">

• Validate early and often. Running your HTML through the W3C validator regularly helps catch these small typos before they cause confusing bugs in production.

Learn more:

MDN Reference

MDN Web Docs: maxlength attribute

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MDN Reference

MDN Web Docs: aria-required attribute

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MDN Reference

MDN Web Docs: input element

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