If your onsale filter is not working, check in wp-admin > Settings > Super Speedy Filters > URL Structure tab.

Scroll down and you’ll find three settings related to the onsale configuration.

1. Pretty Permalinks – you can have /onsale/product-category/toys/ or /product-category/toys/?onsale=1
2. On sale slug – you MUST enter something here – we default it to ‘onsale’ – do not delete it. If you wish you can alter it to your own language but it must have a value.
3. Run SQL to add/update onsale flag – this needs to be run ONCE and then we will maintain it for you.