searx/searx/templates/search.html

<form method="post" action="/" id="search_form">
<div id="search_wrapper">
    <input type="text" id="q" class="q" name="q" tabindex="1" autocomplete="off" {% if q %}value="{{ q }}"{% endif %}/>
    <input type="submit" value="" id="search_submit" />
</div>
    <div>
    {% include 'categories.html' %}
    </div>
</form>