Free Iframe Tester

Free Iframe Tester is a web-based tool that allows developers to test how websites behave when embedded in iframes. It provides real-time previews across desktop, tablet, and mobile viewports, helping identify embedding restrictions and compatibility issues.

Key features include response header inspection (X-Frame-Options and CSP headers), live preview with multiple device sizes, customizable iframe configuration (dimensions, sandbox permissions, responsive settings), and automatic HTML embed code generation. Users can configure sandbox permissions, enable lazy loading, set accessible titles, and preview changes in real-time.

The tool is designed for web developers, frontend engineers, and anyone embedding third-party content who needs to diagnose framing issues, understand embedding policies, and generate production-ready HTML code quickly.