Iframe Tester
Preview iframe embeds and check framing headers
Developer ToolsFree#iframe#testing#web-development
Launches Nov 24, 2026 at 00:00 UTC
What is Iframe Tester?
Iframe Tester is a free web-based tool that allows developers to preview how a target webpage loads inside an iframe. Users enter a public HTTP or HTTPS URL to see a live preview scaled to desktop, tablet, and mobile dimensions. The tool fetches the target site's public response headers separately from the preview to diagnose potential embedding issues.
The application inspects critical framing policies such as X-Frame-Options and Content-Security-Policy directives. When a site refuses to load, the tool explains which header or browser restriction is blocking the connection. It also provides a configuration panel where users can adjust width, height, accessibility titles, lazy loading, fullscreen options, and sandbox permissions. Once configured, the tool generates ready-to-use responsive HTML embed code that can be copied directly into a project.
Iframe Tester features
- Live iframe preview at desktop, tablet, and mobile sizes
- Fetches and displays public X-Frame-Options and CSP headers
- Explains common framing restrictions and connection errors
- Configurable dimensions, sandbox permissions, and accessibility settings
- Generates responsive HTML embed code with copy functionality
- Runs entirely in the browser with no installation required
Who uses Iframe Tester and for what
- Preview how a third-party widget or article loads in an iframe before deployment
- Diagnose why a specific website blocks embedding by checking its security headers
- Generate responsive HTML embed snippets for client websites or internal dashboards
- Test different sandbox permission combinations to balance functionality and security
- Verify framing behavior across desktop and mobile viewports during development
Iframe Tester FAQ
Is Iframe Tester free?
Yes, the tool is completely free to use.
What is Iframe Tester used for?
It lets you preview a webpage inside another webpage, inspect public response headers like X-Frame-Options and CSP to identify framing restrictions, and generate responsive HTML embed code.
Does Iframe Tester work on Mac?
The website does not specify platform requirements, but it runs directly in any modern web browser.
Can I embed any website with this tool?
No. The website owner controls where their content can be embedded. The tool respects those restrictions and will show why a site refuses to connect if headers block it.
Does a successful header check guarantee my iframe will work?
No. The server checks a public, unauthenticated response. Your browser may receive different headers or redirects due to cookies, sandbox permissions, nested ancestors, or the parent page’s own frame-src policy. Always verify the preview and your actual integration.
Can this tool inspect iframe cookies or JavaScript errors?
Not for arbitrary third-party sites. Browser same-origin rules prevent access to their document, cookies, storage, and console. You would need to use your browser’s developer tools or add explicit cooperation in an app you control.
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