Squarespace

<form id="surveyowl-form">
  <label for="so-name">Name</label>
  <input id="so-name" name="name" required />

  <label for="so-email">Email</label>
  <input id="so-email" name="email" type="email" required />

  <label for="so-message">Message</label>
  <textarea id="so-message" name="message" rows="5" required></textarea>

  <button type="submit">Send message</button>
  <p id="surveyowl-status" role="status"></p>
</form>

<style>
  #surveyowl-form { max-width: 480px; font-family: inherit; }
  #surveyowl-form label { display: block; margin: 0 0 4px; }
  #surveyowl-form input,
  #surveyowl-form textarea { display: block; width: 100%; box-sizing: border-box; margin: 0 0 14px; padding: 8px; font: inherit; }
</style>

<script>
  (function () {
    var form = document.getElementById('surveyowl-form');
    var status = document.getElementById('surveyowl-status');
    var button = form.querySelector('button[type="submit"]');

    form.addEventListener('submit', function (event) {
      event.preventDefault();
      button.disabled = true;
      status.textContent = 'Sending…';

      fetch('https://api.surveyowl.co/v1/submit/YOUR_FORM_PUBLIC_KEY', {
        method: 'POST',
        body: new FormData(form)
      })
        .then(function (response) {
          return response.json().then(function (result) {
            if (!response.ok) {
              var message = typeof result.error === 'string' ? result.error : result.error && result.error.message;
              throw new Error(message || 'Could not send the form.');
            }
          });
        })
        .then(function () {
          form.reset();
          status.textContent = 'Thanks — your message was sent.';
        })
        .catch(function (error) {
          status.textContent = error.message;
        })
        .then(function () {
          button.disabled = false;
        });
    });
  })();
</script>