An EmailJS alternative built for contact forms.

Two different shapes

EmailJS is an email sender for the browser. You install its SDK on your website, connect an email service in the EmailJS dashboard, design a template, and the page sends the email using your public key. The message exists as an email and as an entry in EmailJS’s history, kept for 7 days on Free and 30 days on paid plans. That is a good fit when you want replies to thread in your own mailbox or you need attachments and templates.

Heartdove is a form backend. The browser posts the form to one endpoint; the submission is stored in your inbox before any email is sent; the alert goes out from the Heartdove sending domain and is tracked until it is delivered or bounces. Nothing of yours is connected, there are no mail credentials anywhere in the setup, and the message is still there if the email is not.

Side by side, checked 20 October 2026

EmailJS figures come from emailjs.com/pricing and the EmailJS docs index as read on 20 October 2026. The pricing page shows more than one request figure for its Professional and Business plans, so only the Free and Personal figures are quoted. Heartdove figures come from the pricing page.

Dropped or held

EmailJS’s pricing page says it does not charge automatic overage fees, sends notifications at 80, 95 and 100 percent of the monthly limit, and safely drops additional requests once the limit is reached. Upgrading restores sending.

Heartdove also has no overage fees, and handles the limit differently: a submission above the allowance is stored, shown as held, and released automatically when the allowance resets.

What a public key in the page can do

Both services put a public key in your page. With EmailJS, the key is used to send email through the templates and service in your account, and EmailJS offers an allowlist and CAPTCHA verification to control that. With Heartdove, the key only identifies the form; a post is accepted only from the website addresses you registered, is rate limited, and is scored for spam with quarantine. The key cannot send email anywhere else and cannot read anything back.

When EmailJS fits better

• You want the email to come from your own mailbox so replies thread naturally.
• You need attachments, or an automatic reply to the visitor from a designed template.
• You are sending something that is not a form submission at all, such as a notification from an app.

Heartdove does none of those today. It sends one alert email per submission, text only, and keeps the record.

Switching a form from EmailJS

Remove the EmailJS script and the emailjs.send call. Either post a plain form to the endpoint, or keep your JavaScript and post JSON with fetch. Register the website address, add the access key, and keep the hidden trap field.

<form action="https://submit.heartdove.com/v1/submit" method="POST">
  <input type="hidden" name="access_key" value="YOUR_ACCESS_KEY" />
  <label>Email <input type="email" name="email" required /></label>
  <label>Message <textarea name="message" required></textarea></label>
  <!-- Hidden spam trap: people never see it, bots tick it -->
  <input type="checkbox" name="botcheck" tabindex="-1" autocomplete="off" style="display:none" />
  <button type="submit">Send message</button>
</form>

const response = await fetch('https://submit.heartdove.com/v1/submit', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'Idempotency-Key': crypto.randomUUID(), // reuse it when you retry
  },
  body: JSON.stringify({
    access_key: 'YOUR_ACCESS_KEY',
    // turnstile_token: token, // only if the form uses Cloudflare Turnstile
    fields: { email, message },
  }),
});

const receipt = await response.json();
// 202 { success: true, data: { id, status: 'accepted', duplicate: false } }

Questions

Keep reading

• Send an HTML form to email
• Formspree alternative
• React contact form without a backend