Comparison

Check your website form by URL

Paste the address of a page with a form. The checker reads the page once and tells you what will stop messages from arriving, with a fix for each problem.

Short answer: Enter a public page address and press Check. You get concrete issues per form, such as a missing action, fields without a name or no spam protection. Nothing is ever submitted to the site.

Check a page

The checker works with any form, not only Formgong forms. It is free and you don't need an account. It looks at the HTML the page sends, so it works best on the published site.

We read the page once and never submit anything to it.

What the checker looks for

  • A form without an action, or an action that still holds a placeholder such as YOUR_FORM_ID.
  • An action that points to localhost, a private address or an unknown host.
  • method GET on a contact form, which puts the message in the URL.
  • Fields without a name attribute. The browser never sends them.
  • An email field that is not type="email", or no email field at all.
  • No honeypot and no CAPTCHA, so nothing stops spam bots.
  • For Formgong forms: a missing or placeholder access key, a key that does not exist, and a missing botcheck honeypot.

What it can't see

The checker reads HTML. It does not run JavaScript. Many sites built with React, Vue or an AI builder create the form in the browser, so the HTML has no form yet. In that case the checker says so instead of guessing. It also can't see where a script sends the data. For those sites, send one test message, or paste the form code into the prompt for your tool.

Forms inside an iframe (Google Forms, Typeform and similar) are run by that service, so the checker only names it.

Safety and privacy

The checker sends one GET request to the page, with up to 3 redirects, and never submits a form to the site. It only fetches public addresses on the normal web ports. Local, private and internal addresses are refused before any request, and so is every redirect that leads to one. Pages larger than 512 KB are cut, and slow sites stop after 8 seconds.

We don't store the page or the result. A short counter limits each visitor to a few checks every 10 minutes. For a Formgong key we only say whether the form exists. More details, such as allowed domains and a test button, appear only for the signed-in owner of that form.

After the check

Most problems are fixed by asking your builder to rebuild the form with a clear spec. Use the copy-paste prompts for Lovable, Bolt, v0, Cursor, Claude Code, Windsurf or Replit. For a coding agent that keeps editing the project, add the Formgong rules file so the fix stays in place.

Questions

Does the checker send a test message to my site?

No. It only reads the page. The single exception: the signed-in owner of a Formgong form can send one test submission to their own form, and only to Formgong.

Why does it say my form is built with JavaScript?

Your page sends little or no form HTML and builds the form in the browser. The checker does not run scripts, so it can't judge that form. Send one test message to be sure it works.

Does it work with forms that are not on Formgong?

Yes. All general checks work for any form backend. Only the access key checks are specific to Formgong.

Can it check pages behind a login?

No. It fetches the page like a visitor who is not signed in, so it only sees public pages.

Sources

Checked on 04.10.2026 against these public pages: OWASP SSRF Prevention Cheat Sheet, MDN: <form>, Formgong /agents.md.

← Formgong