The ISINDEX Tag

One tag that produced an entire search box. The web's first form control.

In 2026: Removed from browsers between 2014 and 2017, Chrome first and Firefox last. It predates FORM: the browser drew a text field, and pressing enter re-requested the same URL with the text appended as a query.

Where it came from: HTML Tags, 1991, and HTML 2.0 (RFC 1866), 1995. Wikipedia ↗

<!-- In the HEAD, or the BODY, both were allowed -->
<isindex prompt="Search this site: ">

<!-- With its own handler, which came later -->
<isindex prompt="Find: " action="/cgi-bin/search.pl">

<!-- What replaced it -->
<form action="/cgi-bin/search.pl" method="get">
  Search this site: <input type="text" name="q">
</form>