How to add product filters to the Horizon theme

Filters fix that. On Horizon you have three routes: the theme editor alone, Shopify's free Search and Discovery app, or Sledge. Here is each one, including where it stops.

Option A: switch on Horizon's built-in filtering

Horizon displays Shopify's filtering natively; the theme editor decides whether shoppers see it.

1. In Shopify admin, open Online Store, Themes and click Customize on Horizon.
2. Open a collection page inside the preview.
3. Select the section that lists your products and switch on filtering.
4. Choose the layout Horizon offers and save.

Your collection pages now show Shopify's standard filters: availability, price, variant options like size and color, and product type. For a small catalog with tidy product data, that is an honest stopping point, at zero cost.

Where it stops: the theme editor decides where filters sit, not what they are. Styling is limited, so color options read closer to a checklist than a palette, and visual swatches barely figure. There are no merge controls, so "Navy", "navy blue", and "Dark Navy" squat on three separate rows. And the filter list itself is managed elsewhere, which is Option B.

Option B: manage the filters with Shopify's Search and Discovery app

Search and Discovery is Shopify's own free app, and on Horizon it is less an add-on than the engine. The app decides which filters exist; Horizon displays what it defines.

1. Install Search and Discovery from the Shopify App Store, if it is not on your store already. Free.
2. Open the app and go to Filters.
3. Add or remove filters: availability, price, variant options, product type. Rename labels, so "Color" can read "Finish" if that is how your store talks.
4. Reorder the list. Horizon picks up every change automatically.

The right first stop if your needs end at the basics: full control over the filters, free, from the company that builds the platform.

Where it stops: styling and visual swatches stay limited, so a color filter still reads as words, not colors. There are no per-value merge controls, so the Navy problem survives; the only fix is renaming option values on the products themselves, one at a time. And a filter here only narrows the grid. Nothing about it sells.

Option C: add Sledge filters tuned for Horizon

Sledge ships tuned for Horizon, so filters land in the right place on the first load, styled to match the theme. No code, no theme file edits, no block taken from your layout.

1. Install Sledge from the Shopify App Store and start the 14-day free trial.
2. Switch on the Sledge app embed in the theme editor. One toggle.
3. Pick your filter groups: sizes, price ranges, vendor, tags, metafields, and colors as real swatches. Merge stray values, so "Navy" and "navy blue" become one tidy row.
4. Preview a collection and publish. Sledge detects Horizon and places the filter sidebar or flyout to match the theme's layout.

Beyond Options A and B: swatches shoppers see instead of read, a price slider instead of typed numbers, and a product count on every value, so shoppers see what a filter will return before they tap. Results update without a page reload. Filters that sell, not just sort.

And because the same engine powers Sledge search, the same filters work on your search results page too.

Horizon alone, Search and Discovery, or Sledge?

The honest read: a tidy catalog that fits the standard filter set does fine on Option B, free. The moment shoppers need swatches, metafield filters, or one clean menu on top of messy option data, that is Sledge's job.

Related reading

Sledge on Horizon · Filters · What is a product filter? · What is a color swatch?