Why doesn't my form work on GitHub Pages?

GitHub Pages can't run server code, so there's nothing to receive a POST request. You need an external form backend.

Does it work with a custom domain?

Yes. Add both your custom domain and username.github.io to the allowlist if you use both.

How to add a contact form to GitHub Pages

GitHub Pages only serves static files, so a contact form needs an external endpoint to receive submissions. Point the form's action at a FormSubmit endpoint and it works — FormSubmit stores the message, filters spam and emails it to you.

Steps

Sign in to FormSubmit and create a form.
Add the form to any HTML page in your repository (or your Jekyll/Hugo/Astro source):

contact.html

<form action="https://formsubmit.app/f/YOUR_FORM_ID" method="POST" class="fs-form">
  <div class="fs-field">
    <label for="fs-name" class="fs-label">Name</label>
    <input id="fs-name" type="text" name="name" placeholder="Jane Doe" required class="fs-input">
  </div>
  <div class="fs-field">
    <label for="fs-email" class="fs-label">Email</label>
    <input id="fs-email" type="email" name="email" placeholder="jane@example.com" required class="fs-input">
  </div>
  <div class="fs-field">
    <label for="fs-message" class="fs-label">Message</label>
    <textarea id="fs-message" name="message" rows="5" placeholder="How can we help?" required class="fs-input"></textarea>
  </div>
  <!-- Honeypot: leave this hidden field empty to catch bots -->
  <input type="text" name="_gotcha" tabindex="-1" autocomplete="off" style="display:none">
  <!-- Optional: where to send people after submitting -->
  <!-- <input type="hidden" name="_redirect" value="https://yoursite.com/thanks"> -->
  <button type="submit" class="fs-button">Send</button>
</form>

<style>
  .fs-form { max-width: 32rem; margin: 0 auto; display: grid; gap: 1.1rem; font-family: system-ui, sans-serif; }
  .fs-field { display: grid; gap: 0.35rem; border: 0; padding: 0; margin: 0; }
  .fs-label { font-size: 0.875rem; font-weight: 600; color: #18181b; }
  .fs-input { width: 100%; box-sizing: border-box; border: 1px solid #d4d4d8; border-radius: 0.5rem; padding: 0.6rem 0.75rem; font: inherit; font-size: 0.9rem; }
  .fs-input:focus { outline: 2px solid #6366f155; border-color: #6366f1; }
  .fs-choice { display: flex; align-items: center; gap: 0.5rem; font-size: 0.9rem; }
  .fs-help { font-size: 0.75rem; color: #71717a; margin: 0; }
  .fs-button { background: #18181b; color: #fff; border: 0; border-radius: 0.5rem; padding: 0.7rem 1rem; font-weight: 600; cursor: pointer; }
  .fs-button:hover { background: #27272a; }
</style>

Commit and push. GitHub Pages rebuilds in a minute or two.
In the form's settings, add yourname.github.io (and your custom domain, if any) to the allowlist.
Submit a test.

Project sites

For project pages served at yourname.github.io/project/, the allowlist entry is still yourname.github.io — paths don't matter.

Using a static site generator

Jekyll (GitHub Pages' built-in generator): see the Jekyll guide.
Hugo, Astro, Eleventy and others via GitHub Actions: see the Hugo, Astro and Eleventy guides.

Keep your email private

With FormSubmit your email address never appears in the page source — unlike mailto: links or services that put your address in the form action — so scrapers can't harvest it.