Squarespace vs Alternatives (Designer POV)
Which Squarespace plan do I need to use plugins and code injection?
You need a Core plan or higher for sitewide Code Injection (Header and Footer), which is how most Squarespace plugins are installed. On legacy plans this was the Business plan or higher. The new entry-level Basic plan does not allow JavaScript in code blocks, so the per-page Code Block workaround only ever worked on the older Personal plan, not on Basic.
Which plan enables sitewide Code Injection
Most Squarewebsites plugins install by pasting a snippet into Squarespace’s sitewide Code Injection (Header for CSS, Footer for JS). On the current plans this feature starts at the Core plan and above; on legacy plans it was the Business plan and above (Squarewebsites). At that level the snippet applies across the whole site, which is what the plugins are designed for. Commerce plans also enable Code Injection, so a store running Universal Filter or Custom Table Block works the same way. Squarespace documents Code Injection as a premium feature (Squarespace; Squarespace).
Basic plan and the legacy workaround
The new entry-level Basic plan does not support JavaScript in code blocks — it allows only CSS, HTML, and Markdown — so it cannot run most plugins even through a per-page block. Squarespace’s own Code Blocks article confirms JavaScript in code blocks is limited to the Core, Plus, Advanced, Business, and Commerce plans (Squarespace). The per-page Code Block or Markdown workaround only ever applied to the older legacy Personal plan, where it was still less reliable, harder to maintain across many pages, and could be removed by Squarespace over time, so it was treated as a hack rather than a supported path (Squarewebsites).
Plan naming note
Squarespace announced a plan rename in February 2025, so the exact plan labels and prices may have changed. The reliable rule is: choose a Core plan or higher (Business or higher on legacy plans) for sitewide Code Injection, and note that the new Basic plan cannot run the Code-Block workaround because it blocks JavaScript (Squarespace).
See the full Squarespace vs Alternatives (Designer POV) 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 · www.squarespace.com