HTML readonly Attribute: Reference and Examples

The readonly attribute is a small instruction attached to an HTML element. Its job is to make an eligible control uneditable but still submittable. It is easier to remember when you can see it in a real piece of markup.

What readonly is used for

Make an eligible control uneditable but still submittable. The attribute appears inside an element’s opening tag. Depending on its definition, it may take a specific string, a number, an enumerated keyword, or be a boolean attribute.

The example below uses it in a input context. Other elements may support it too, or may give the same attribute a different meaning.

Example you can try

<form action="/save" method="post">
    <label for="example-field">Example readonly</label>
    <input id="example-field" name="example_field" type="text" readonly>
    <button type="submit">Save</button>
</form>

How the example works

Look for readonly in the snippet. Here the example shows its presence without a string value. This is a concrete input the browser can interpret; it is not just text shown to the reader.

Readonly values are normally still submitted. Disabled controls are typically not submitted.

Values and important behavior

Use the value format shown by the HTML definition. Do not assume that a value accepted in one attribute also works in another. When a browser ignores an invalid value, inspect the element and correct the markup.

This detail matters most when the page receives user input, navigates to another document, or loads an external resource. In those cases, check the browser behavior and any server-side requirements separately.

Small practice task

Copy the code and change readonly to another sensible value, or remove it entirely if it is optional. Test the difference in the browser and inspect any submitted value or network request.

Common Beginner Mistakes

• Readonly values are normally still submitted. Disabled controls are typically not submitted.
• Using readonly on an element that does not support it.
• Believing that an HTML hint or client-side check replaces real server validation or a security policy.

Key Takeaways

• readonly is used to make an eligible control uneditable but still submittable.
• Readonly values are normally still submitted. Disabled controls are typically not submitted.
• Choose valid values and test the result instead of guessing what the browser will do.