For site owners

Add a free link checker to your site

Help your visitors check suspicious links before they click. Copy one snippet of HTML onto your website, blog, intranet, or community page - no JavaScript, no tracking, no sign-up.

Why add it

Genuinely useful. Your visitors get an instant, plain-language safety check for any link, powered by the same free tool people already trust.
Private and lightweight. The snippet is plain HTML with inline styles - no JavaScript, no cookies, no third-party requests until someone chooses to check a link. It works under any Content Security Policy.
Free, forever. Cactus Security is a free public-good project. Embedding it costs nothing and links back to a resource you can stand behind.

Preview

The widget

Copy this HTML and paste it where you want the checker to appear. It opens results on cactus.net in a new tab.

<!-- Cactus Security link checker -->
<form action="https://cactus.net/CheckUrl" method="get" target="_blank" rel="noopener"
      style="max-width:360px;font-family:system-ui,-apple-system,sans-serif;border:1px solid #d6e0d8;border-radius:12px;padding:16px;background:#f7faf8">
  <label style="display:block;font-size:14px;font-weight:600;color:#14301f;margin-bottom:8px">Is this link safe? Check it for free</label>
  <input type="url" name="u" required placeholder="https://example.com"
         style="width:100%;box-sizing:border-box;padding:8px 10px;border:1px solid #c3d2c8;border-radius:8px;font-size:14px;margin-bottom:8px">
  <button type="submit"
          style="width:100%;padding:9px;border:0;border-radius:8px;background:#17804a;color:#fff;font-size:14px;font-weight:600;cursor:pointer">Check this link</button>
  <div style="margin-top:8px;font-size:12px;color:#5a6b60">Powered by <a href="https://cactus.net" style="color:#17804a">Cactus Security</a></div>
</form>

Just a link

Prefer a simple text link instead of a form? Use this minimal badge.

🌵 Check a link with Cactus Security

<a href="https://cactus.net/CheckUrl" style="font-family:system-ui,sans-serif;font-size:14px;color:#17804a;text-decoration:none">&#127797; Check a link with Cactus Security</a>

How it works

When a visitor enters a link and submits, their browser opens cactus.net/CheckUrl with that link, where our normal analysis runs. The widget itself sends nothing until then, and we never store the result.