How do I add a plugin to my Squarespace site?
You add a Squarewebsites plugin by pasting its code snippet into your site, then configuring it. On a Core plan or higher (Business or higher on legacy plans), you paste the snippet into sitewide Code Injection. The new Basic plan blocks JavaScript, so the per-page Code Block workaround only worked on the older Personal plan. After purchase you receive the code file and an installation guide.
Step 1: Check your plan’s method
Your Squarespace plan determines how you install. On a Core plan or higher (Business or higher on legacy plans), Squarespace enables Code Injection for sitewide Header and Footer placement. The new Basic plan blocks JavaScript in code blocks, so the per-page Code Block route only worked on the older legacy Personal plan (Squarewebsites). Squarespace’s own documentation confirms JavaScript in code blocks is limited to the Core, Plus, Advanced, Business, and Commerce plans (Squarespace), that Code Injection is a premium feature (Squarespace), and how to use it (Squarespace).
Step 2: Paste and configure
After purchase you receive a code file (typically a .txt file) plus a URL and password to an installation guide. Follow the guide’s “Simple Way” section: paste the code into Code Injection (or, on a legacy Personal plan, a Markdown block as a workaround), refresh your site, and then configure the options to match your content (Squarewebsites). For Universal Filter specifically, the “Get Filter Config” button generates the setup code for non-coders (Squarewebsites).
Step 3: Get help if needed
Every plugin includes free basic-setup support to get the standard configuration working (Squarewebsites). If you run into trouble, reach out via email or the Slack support forum (Squarewebsites).
See the full Squarespace Plugins — General product page on squarewebsites.org for live pricing, demos, and setup details.
Sources: squarewebsites.org · squarewebsites.org · support.squarespace.com · support.squarespace.com · support.squarespace.com