Have you ever started typing into a form and had your browser suggest a saved value? HTML can help the browser decide which value belongs in which field. The autocomplete token bday is used for full date of birth.
What bday tells the browser
Full date of birth.
This is a hint, not an instruction to fill a value automatically. Browsers and password managers consider settings, saved data, permissions and other signals before offering suggestions.
Example form field
<form action="/example" method="post">
<label for="detail-field">Date of birth</label>
<input id="detail-field" name="detail" type="date" autocomplete="bday">
<button type="submit">Continue</button>
</form>Understanding the example
The autocomplete="bday" attribute labels this field for autofill. Its visible <label> still tells people what to type, and its name attribute determines the key sent when a form is submitted.
Only collect birth dates when necessary; this is personal data.
Sensitive information deserves extra care. Use HTTPS, collect only what is needed, avoid logging secrets, and validate received data on the server. Payment card fields should generally use a compliant payment provider rather than custom storage.
Try it yourself
Save the example as an HTML file, and test the field with browser autofill enabled. Inspect the autocomplete value and compare it with the field label. Browser behavior depends on available saved information, so a missing suggestion is not necessarily an HTML mistake.
Common Beginner Mistakes
- Only collect birth dates when necessary; this is personal data.
- Leaving out the visible label because the browser might autofill the field.
- Treating autofill suggestions as verified or safe data.
Key Takeaways
bdaydescribes full date of birth.- Only collect birth dates when necessary; this is personal data.
- Autocomplete helps users; it does not replace labeling, accessibility or validation.