macOS Captive Portal Preview
Preview and test your captive portal in an authentic macOS CNA (Captive Network Assistant) window environment at 900×572px resolution. Load via URL or paste HTML source directly to bypass mixed content restrictions.
Instructions
Enter an HTTPS URL and click Preview. The page must allow iframing (no X-Frame-Options or CSP restrictions).
Important Notes:
- HTTPS URLs only — browsers block HTTP content inside an HTTPS page (Mixed Content policy)
- Some websites block iframing via X-Frame-Options or CSP headers
- Use Paste HTML mode to preview local HTTP servers without any restrictions