Squarespace Developer Platform FAQ

Answers to common questions about Squarespace's Developer Platform, a version 7.0 feature where coders can customize their site beyond what's available in Site Styles.

Last updated January 21, 2025

This guide covers common questions about The Squarespace Developer Platform, an advanced tool that developers can use to customize their site beyond our built-in custom code tools. The Developer Platform is designed for people with advanced coding knowledge. If you’re already using the Developer Platform, visit our Developer Docs.

Accessing this feature

The Developer Platform is available only in version 7.0 on the following plans. To learn more, visit Choosing the right Squarespace plan:

  • Core
  • Plus
  • Advanced
  • Business
  • Commerce Basic
  • Commerce Advanced
  • Legacy Personal (no longer available)
  • Website Commerce (no longer available)
  • Website Professional (no longer available)

If your site is on version 7.1, you can still add custom code in other ways.

Who is the Developer Platform for?

Most Squarespace users don’t need the Developer Platform because Squarespace provides built-in options like custom HTML, CSS, and Javascript, which allow you to highly customize your site. Some users, like developers and design agencies, require more customization that they can only achieve by writing custom code.

The Developer Platform is only recommended for advanced developers who have experience creating custom websites, and have HTML, LESS CSS, JSON-T, and Github knowledge.

What can I customize with the Developer Platform?

After enabling developer mode, you can:

  • Create a custom 7.0 site template from scratch
  • Modify an existing 7.0 template
  • Access your template's markup, style sheets, scripts, and template design assets

You can’t:

  • Create or modify a custom 7.1 site
  • Access content added via the CMS
  • Add server-side custom code
  • Modify default scripts and styles
  • Modify existing editing tools
  • Customize blocks
  • Customize cover pages

To learn more, visit developers.squarespace.com.

How will my site change after enabling developer mode?

If your site still includes demo content, this content will disappear after enabling developer mode. Also:

  • You won't be able to switch templates.
  • Your template won't receive any template updates from Squarespace. Your site will still receive platform-wide updates.

Otherwise, there won’t be any changes to your live site until you update your code.

What happens if I disable developer mode?

Note

Disabling developer mode after adding customizations can have a big impact on your site’s appearance and functionality. Review this section carefully before you disable it.

When you disable developer mode, customizations you made on the Developer Platform will disappear. Also, any changes you made in your site's built-in style editor will disappear, even if you made the changes before enabling developer mode. Your site will return to default Squarespace settings and styles, and custom layouts, features, and integrations will stop working:

  • Custom code is disabled
    • CSS is removed and your site returns to default Squarespace styles
    • HTML disappears
    • JavaScript and any custom interactive functionality stops working
  • Site settings reset to Squarespace default settings
  • Custom layouts revert to Squarespace default layouts
  • Custom collections disappear
  • Custom integrations stop working
  • Assets you uploaded disappear

Disabling developer mode may also affect these content areas:

  • Navigation - This reverts to your site’s original navigation menu order, including pages in dropdowns and index pages. Pages in your navigation move to the Not linked section of the Pages panel. You can move pages around your navigation to rebuild your navigation after you disable developer mode.
  • Custom blog post types - These revert to default post types. You can edit the content you added, but you can’t edit your custom fields.
  • Sidebars, headers, and footers - Content added to these areas on the Developer Platform disappears.

Keep in mind, disabling developer mode doesn’t affect the custom code in your Custom CSS and Advanced code injection panels. We recommend saving your site files and your developer platform code locally on your computer before you disable developer mode. If you turn developer mode back on, some customizations will reactivate. However, it may not be possible to recover all customizations.

What happens if I use developer mode during a trial?

The Developer Platform is a premium feature. During a trial, you have full access to developer mode. Trial sites with developer mode enabled don't expire, giving you as much time as you need to build your custom Squarespace site.

When upgrading to paid service, choose the Website Business plan or higher to continue using developer mode.

If you choose the Personal Plan, we recommend turning developer mode off first. If you leave developer mode on, it stays on and prevents your site from receiving template updates, but you can't make further changes.

What happens if I use developer mode and then downgrade?

If you downgrade to the Personal plan after activating developer mode, you’ll have full access to developer mode until the end of your current billing period. After your new subscription begins on the Personal plan:

  • The developer mode customizations you made to your site remain.
  • Developer mode stays on, but it’s not possible to make more changes.
  • Because developer mode is still on, you won't receive template updates.
  • To regain access to developer mode, upgrade to the Website Business plan or higher.

Why can't I log in?

If you see an Authentication failed error when you try to log in, it may be because you've enabled two-factor authentication, or that you use social login. In either case, you'll need to create an app password to log in. Alternatively, you can disable two-factor authentication and/or switch your login method to email and password.

Can I contact Customer Support for help?

You can contact us with questions about enabling and getting started with the Squarespace Developer Platform. We can't help you write or troubleshoot custom code solutions, however, as these topics fall outside our scope of our support. For this reason, we only recommend the Developer Platform if you have advanced knowledge of coding languages and can troubleshoot code issues independently.

If you have questions about custom code, try these resources:

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  • Get help from our community

  • Get help from our community on advanced customizations.

  • Hire a Squarespace Expert

  • Stand out online with the help of an experienced designer or developer.