Yes. SeaText works on a Squarespace trial without a custom domain. A published trial site already has a real Squarespace URL, and that URL is enough for SeaText to install, activate, and link to your account.

What matters is not whether the domain is custom. What matters is whether your site is published and whether you can paste JavaScript into Squarespace’s Code Injection area. A default Squarespace address meets that test.

What SeaText needs to work on a Squarespace trial

Use these four conditions as your checklist:

• A valid, real domain. The default Squarespace trial URL qualifies. Do not use localhost.
• A Squarespace site that can be published. Trial sites can be published. Code changes only apply after publishing.
• Access to Code Injection. In Squarespace, this is under Settings > Developer Tools.
• A SeaText account. You need the account before you can copy the JavaScript snippet.

If those four conditions are true, SeaText will work. A custom domain is not on the list.

Why a Squarespace trial’s default domain is enough

SeaText’s integration guide does not say that you need a paid or custom domain. It says that you need a valid, real domain. It also warns against development URLs such as localhost, which are restricted for security reasons. Dynamic development domains may not work because SeaText may not be able to reliably associate traffic with your account.

A Squarespace trial URL is not localhost. It is a real page on the public web when the trial site is published. That is enough for the SeaText script to load and for traffic to be associated with your account.

SeaText also does not need to change DNS or register a domain. It runs as JavaScript in your page header. From the script’s point of view, the page has a URL, the URL is public, and a visitor can load it. The branding or ownership of the domain is irrelevant.

Trial URL or custom domain first: trade-offs

Although a custom domain is not required, it is still worth choosing your setup deliberately. The table below compares the common paths.

Which setup should you choose?

Choose the trial-as-is path if you want to validate SeaText quickly and you are comfortable setting up another account for a final custom domain later.

Choose the connect-custom-domain-first path if you want one SeaText account that matches the final domain from the start and you do not mind waiting until the domain is live.

Choose the separate-accounts path if you need the trial site and the production site live at the same time. The SeaText guide is clear: each account is linked to a single primary URL, so separate domains need separate accounts.

Here is the decision rule: install on the trial now when the trial site is published, Code Injection is available, and you accept that your final domain may require a separate SeaText account. If you want to avoid that extra step, connect your final domain before you install.

How to install SeaText on a Squarespace trial

The install process is the same whether your site uses a custom domain or the default Squarespace URL. Follow these steps:

1. Create a SeaText account. The SeaText guide says you need an account before you can install the script.
2. Copy the JavaScript code from the SeaText dashboard.
3. Log in to Squarespace and open the Website panel.
4. Click the three-dot icon for the site and select Settings.
5. Scroll to Developer Tools near the bottom of the settings page.
6. Click Code Injection.
7. Paste the JavaScript code into the Header area.
8. Click Save.
9. Publish the site so the change applies.

Activation checks after install

Installing the code is not the last step. The SeaText guide includes these activation checks:

• Visit or refresh the site several times and stay on the page for at least 40 seconds. This activates the AI and links it to your account.
• Wait at least five minutes. You should then see your website name next to the SeaText logo at the top of the SeaText page.
• If the website name does not appear after 10 minutes, contact SeaText support. The guide says this could indicate an installation issue.

Until activation happens, the AI stays inert. Simply pasting the code does not rewrite your site.

Key facts at a glance

Limitations and when this advice stops applying

The trial-sans-custom-domain answer is “yes,” but it has limits. Here are the cases where the answer changes.

One account is tied to one primary URL

Each SeaText account is linked to a single primary URL. If you install on a trial site and later launch a different custom domain, that new domain is a different URL. Plan to create a separate account for the new domain if the old trial URL and the new production URL both need SeaText.

Localhost and temporary development domains do not count

SeaText restricts development URLs such as localhost for security reasons. Dynamic development domains may also fail because SeaText cannot reliably associate traffic with your account. A Squarespace trial URL avoids this problem because it is a real domain, not a local test address.

Code Injection must be available

The install method described here depends on Squarespace letting you reach Settings > Developer Tools > Code Injection. If your trial site does not expose that section, this integration path will not work. Check your own Squarespace trial settings before deciding.

The site must stay published

The SeaText guide says to ensure your website is published so changes apply. An unpublished trial site has no live visitor page for the script to run on. Keep the trial published for the full activation and testing period.

A trial is still temporary

SeaText can run during the trial, but a trial site is not a permanent home. When the trial ends and the site is no longer published, there is no live public URL for SeaText to process. If your goal is a long-term setup, move to a paid Squarespace plan and use the final domain before relying on that setup for production traffic.

SeaText and Squarespace terms, in plain English

• Primary URL: the exact website address attached to a SeaText account. Traffic is linked to this address.
• Default Squarespace domain: the generated URL that Squarespace gives you when you have not connected a custom domain.
• Custom domain: a domain you own, such as example.com, connected to your Squarespace site.
• Code Injection: the Squarespace settings area where you can add custom code to your site.
• Header area: the code section that loads near the top of the page. SeaText’s snippet should be pasted there.
• Dynamic development domain: a temporary development URL that changes between sessions. SeaText warns that these may not work reliably.

Frequently asked questions

1. Will SeaText work on a Squarespace trial without a custom domain? Yes. A trial with the default Squarespace URL meets the important requirements: a real, publishable web page and access to Code Injection.
2. Do I need to add JavaScript manually? Yes. SeaText’s Squarespace integration requires pasting a JavaScript snippet into the Header area under Code Injection. The SeaText dashboard provides the snippet.
3. Can I use localhost to test SeaText? No. Localhost URLs are restricted for security reasons. Use a valid, real domain instead, which is why a Squarespace trial URL works well.
4. Can I use one SeaText account for the trial and for my production domain later? Only if they share the same primary URL. SeaText links each account to a single primary URL. If your final domain is different, create a separate account for it.
5. Why do I not see my website name in SeaText after installing? First, make sure the site is published. Then visit or refresh the site several times and stay on the page for at least 40 seconds. Wait at least five minutes. If it still does not appear after 10 minutes, contact SeaText support.
6. Will SeaText change my content as soon as I paste the code? No. The installation is secure, and the AI remains inert until activated. After installation, you need to follow the activation steps and then turn on the features you want.