How to add a newsletter signup form to your website

You add a newsletter signup form to your website by pasting a small HTML form that posts directly to your newsletter's subscription endpoint. When someone submits it, their email flows straight into your list. It works on any site that lets you add HTML — plain HTML pages, Squarespace, Wix, Webflow, Ghost — with no plugin to install.

There are two ways to do it: paste the HTML form below (full control over the look), or, if you would rather write no code at all, simply link people to your hosted subscription page. Both are covered here.

Yellaro runs managed Listmonk — the open-source newsletter tool — so this form talks to your own instance. Pricing is flat and billed by emails sent, not per subscriber, so a growing signup list never inflates your bill on its own.

Before you start: two settings that make it work

An embedded form only works when both of these are true. Check them first — it saves a lot of "why isn't it working" later:

1. Your public subscription page is turned on. In your Yellaro dashboard, open Settings and enable the public subscription page toggle. This is the switch that allows a form hosted on your own site to submit to your list.
2. The list you're targeting is a public list. A private list will reject public form submissions. You can see each list's type on the Integrations page.

Step 1: Turn on the public subscription page

In the dashboard, go to Settings and switch on the public subscription page. Until this is on, submissions from your website form are rejected, even if everything else is correct.

Step 2: Get your list UUID

Open Integrations in the dashboard. Each list shows two identifiers:

• a List ID (a small number) — used by the WordPress plugin
• a List UUID (a long string like a1b2c3d4-...) — used by embedded signup forms

For an HTML form you want the List UUID. Copy it. While you're there, confirm the list's type is Public.

Step 3: Paste the HTML form onto your site

Drop this into any HTML or embed block on your page. Replace YOURSITE with your own Yellaro subdomain and YOUR-LIST-UUID with the UUID you just copied:

<form
  method="post"
  action="https://YOURSITE.yellaro.com/subscription/form"
  class="newsletter-form"
>
  <input type="hidden" name="l" value="YOUR-LIST-UUID" />

  <label>
    Email
    <input type="email" name="email" required placeholder="you@example.com" />
  </label>

  <label>
    Name (optional)
    <input type="text" name="name" placeholder="Your name" />
  </label>

  <button type="submit">Subscribe</button>
</form>

That's the whole thing. email is the only required field; name is optional. The hidden l field tells your instance which list to add the subscriber to — that's why the UUID matters.

Style it however you like — it's ordinary HTML, so your site's CSS applies. A minimal starting point:

.newsletter-form {
  display: grid;
  gap: 0.75rem;
  max-width: 22rem;
}
.newsletter-form label {
  display: grid;
  gap: 0.25rem;
  font-size: 0.9rem;
}
.newsletter-form input {
  padding: 0.5rem 0.6rem;
}
.newsletter-form button {
  padding: 0.55rem 1rem;
  cursor: pointer;
}

Step 4: Test it

Submit the form with an email address you can check.

• If your list is double opt-in, you'll get a confirmation email — click the link to confirm.
• Then open your list and confirm the subscriber is there. On a double opt-in list they'll sit as unconfirmed until they click the link; on a single opt-in list they're added right away.

If nothing arrives, the usual causes are the public subscription page still being off (Step 1), the list not being public (Step 2), or a mistyped UUID.

No-code alternative: just link your subscription page

If you don't want to touch HTML at all, you don't have to. Your instance already hosts a ready-made subscription page at:

https://YOURSITE.yellaro.com/subscription/form

Add a normal link or button to it from your website — in your nav, footer, or a "Subscribe" call to action — and people can sign up there directly. Zero code, and it uses the same double opt-in flow. The trade-off is that visitors leave your page to subscribe, whereas the embedded form keeps them on it.

Using WordPress?

If your site runs on WordPress, there's a dedicated plugin route that avoids hand-written HTML and can also add opt-in at WooCommerce checkout. See how to connect a WordPress signup form to your newsletter for the full walkthrough.