/dd>
    </dl>
<h2>Tools</h2>
    <p data-role="slow-tools">Zopfli and PNGOUT are very good PNG compressors, but are very slow. Disable them if you need to optimize PNG files quickly (leave only AdvPNG for fastest, but still good compression).</p>
    <p data-role="dirty-alpha-tools">Zopfli and OptiPNG will clean RGB values of transparent pixels (known as “dirty alpha”). Disable these two tools if you're optimizing special files that use alpha channel for something else than transparency (e.g. heightmap