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SSL & HTTPS Checker

Check SSL/HTTPS configuration from URL + HTML. Detect HTTPS protocol, mixed content (active/passive), validate HSTS header, estimate http→https redirect, generate recommendations. Honest disclaimer: this tool does NOT make live HTTPS requests. History (localStorage), shareable URL. 100% client-side.

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About SSL & HTTPS Checker

Check SSL/HTTPS configuration from URL + HTML. Detect HTTPS protocol, mixed content (active/passive), validate HSTS header, estimate http→https redirect, generate recommendations. Honest disclaimer: this tool does NOT make live HTTPS requests. History (localStorage), shareable URL. 100% client-side. Everything runs locally in your browser — your data never leaves your device.

How to use

  1. Enter your input in the tool above.
  2. Adjust any options to your preference.
  3. Use the Copy or Download buttons to save the result.
  4. Everything happens locally — your data never leaves your browser.

FAQ

What does the SSL & HTTPS Checker actually check?

Three things: (1) the URL protocol — HTTPS or HTTP, (2) mixed content in pasted HTML — active (scripts/stylesheets/iframes with http://) and passive (images/audio/video), (3) HSTS header from pasted Strict-Transport-Security value. The tool does NOT make live HTTPS requests or inspect TLS certificates — see the disclaimer below.

Why can't this tool make live HTTPS requests?

Two reasons: (1) Browsers block cross-origin HTTPS requests via CORS — we can't read another site's certificate or headers from your browser. (2) It would violate UnQTools' privacy-first principle (no network calls at runtime). To verify a live site's SSL cert and headers, use server-side tools like SSL Labs' SSL Test, securityheaders.com, or curl from your terminal.

What is mixed content?

When an HTTPS page loads resources (images, scripts, stylesheets) over HTTP. Active mixed content (scripts/stylesheets/iframes) is blocked by modern browsers — the page breaks. Passive mixed content (images/audio/video) is loaded but browsers show a 'Not Secure' warning. Both hurt SEO and user trust.

What is HSTS and how do I configure it?

HTTP Strict-Transport-Security (HSTS) tells browsers to only use HTTPS for your site for a specified duration. Configure it via the Strict-Transport-Security response header: max-age=31536000; includeSubDomains; preload. After 1 year of clean HSTS, you can submit to the HSTS preload list (hstspreload.org).

What extra features does this tool have compared to others?

(1) HTTPS protocol detection. (2) Mixed content checker (active vs passive). (3) HSTS header validation. (4) Protocol analysis. (5) http→https redirect estimation. (6) SSL info display (from URL structure). (7) Recommendation engine. (8) Plain-text report copy. (9) Honest disclaimer about live checking. (10) History (localStorage, last 20). (11) Shareable URL.

Is my data sent anywhere?

No. All analysis runs locally on the URL/HTML/header text you paste. History is stored in localStorage on this device only.

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