SEO Analyze
SEO Checker

No Mixed-Content Issues (All Resources via HTTPS) SEO Checker

Scan your page for insecure http:// resources on HTTPS, see a percentage SEO score, and get practical tips to keep all assets served securely.

SEO Score
0%
Optimized

Legend: chars = characters, pts = points.

API: ?api=1

What the metrics mean

  • No Mixed-Content SEO Score: 0–100% quality.
  • chars: character count.
  • pts: scoring points.
  • Signals: each checked rule.
All resources should be fully HTTPS for ranking, trust, and browser compatibility.

No Mixed-Content Issues (All Resources via HTTPS) SEO Checker

Mixed content happens when a page loads over HTTPS but requests some resources over HTTP. It feels like a small technical detail, yet it directly touches security, user trust, browser behavior, and technical SEO. Modern browsers actively warn or block insecure resources, and search engines increasingly expect fully secure pages. A “No Mixed-Content Issues” SEO Checker ensures that every script, style, image, font, video, iframe, and API call on your site is delivered securely through HTTPS, keeping both your users and your rankings protected.

What mixed content is and why it exists

A webpage is considered “mixed content” when the main document is served over HTTPS, but one or more embedded resources are fetched over an insecure HTTP connection. This usually appears after a site migrates to HTTPS but some internal or external links remain hardcoded as HTTP. It also happens when third-party resources, old CDN URLs, legacy plugins, or user-generated content include insecure references.

Even a single insecure resource can undermine the security promise of HTTPS. Attackers can intercept or modify HTTP resources in transit, affecting what users see and how the page behaves. That is why browsers treat mixed content as a real security issue rather than a cosmetic warning.

Active vs. passive mixed content

Mixed content is not all equal. Browsers and SEO audits typically separate it into two categories:

  • - Active mixed content: Insecure resources that can change the page’s behavior or access data, such as JavaScript files, CSS files, iframes, XHR / fetch calls, or WebSocket connections. Active mixed content is the most dangerous and is commonly blocked by browsers.
  • - Passive mixed content: Insecure resources that are usually “read-only,” such as images, audio, or video. Passive content can still be tampered with (for example, swapping images), and browsers may show warnings or partially block these resources depending on policies.

A strong No Mixed-Content Issues Checker should detect both types, but treat active mixed content as a higher-severity problem because it can break functionality and security instantly.

Why mixed content matters for SEO and user experience

Search engines have treated HTTPS as a quality signal for years, and modern technical SEO expects sites to be fully secure. Mixed content can weaken that signal in several ways:

  • - Security warnings reduce trust: Browsers label or warn about insecure elements, making users hesitate or leave the page quickly. Reduced trust often translates into poorer engagement metrics.
  • - Browser blocking breaks pages: When active mixed content is blocked, pieces of your layout or features can fail, leading to broken UI, missing styling, or non-functional tools.
  • - Indirect ranking impact: Higher bounce rates and lower satisfaction signals can reduce organic performance even without a direct “penalty.”
  • - Crawl clarity and efficiency: Search crawlers prefer stable, secure resource delivery. Mixed content creates extra redirects and wasted fetch attempts.
  • - Brand credibility: A site that cannot maintain secure resources across all pages looks outdated or neglected, especially in competitive markets.

In practical SEO terms, fixing mixed content protects both the technical trustworthiness of the site and the behavioral signals that search engines use to evaluate usefulness.

Where mixed content commonly hides

Mixed content can appear anywhere a URL is embedded. Common sources include:

  • - Hardcoded HTTP links in templates: Old theme or layout files that still reference HTTP assets.
  • - Inline styles and scripts: Background images or external script calls inside HTML or CSS.
  • - Images and media libraries: Older uploads stored with HTTP URLs or pulled from insecure sources.
  • - Fonts and icon kits: CSS files or font URLs that default to HTTP.
  • - Third-party widgets: Embedded tools, ads, or analytics scripts loaded from non-secure hosts.
  • - API endpoints: Fetch/XHR calls in JavaScript still targeting HTTP services.
  • - User-generated content: Comments or posts that allow embedded images or links via HTTP.
  • - Legacy redirect chains: “HTTPS” resources that redirect to HTTP at some step.

Your checker should scan full rendered pages and also inspect source HTML and CSS to reliably uncover these hidden cases.

How to fix mixed content issues correctly

Mixed content fixes should be systematic, not one-off patches. Best practices include:

  • - Update all internal resource URLs to HTTPS: Replace HTTP references with HTTPS versions. This includes images, scripts, stylesheets, videos, fonts, and API calls.
  • - Enforce sitewide HTTPS redirects: Ensure that any HTTP request to your domain redirects cleanly to the equivalent HTTPS URL.
  • - Remove or replace insecure third-party resources: If a resource provider does not support HTTPS, use a secure alternative or host the asset yourself.
  • - Fix redirecting resources: A resource that starts on HTTPS but redirects to HTTP still causes mixed content. Correct the final target.
  • - Normalize canonical hosts: Use one consistent secure host (with or without www) so that internal URLs never jump across versions.
  • - Check CMS settings and content stores: Many platforms store absolute URLs in databases. Update these at the root to prevent future insecure inserts.
  • - Protect publishing workflows: Ensure editors and upload tools default to HTTPS for embedded media.

The No Mixed-Content Issues Checker should not only detect problems but also classify them into “easy replace,” “third-party replace,” “redirect fix,” and “API refactor,” so repairs are efficient.

Preventing mixed content long-term

Preventing mixed content is easier than repeatedly fixing it. Prevention strategies include:

  • - Use HTTPS everywhere by default: Ensure new templates and plugins only allow secure URLs.
  • - Centralize asset management: Store and serve core assets from secure, controlled endpoints.
  • - Monitor third-party scripts: Keep an inventory of third-party dependencies and re-audit them regularly.
  • - Validate user-generated inputs: If users can embed media, automatically rewrite HTTP to HTTPS when safe.
  • - Adopt strict security headers when ready: Strong site security policies can block mixed content before it reaches users, but only after your site is fully HTTPS-clean.

A checker that runs on a schedule (daily, weekly, or monthly) is the easiest way to stop mixed content from returning unnoticed.

Implementation rubric for a No Mixed-Content Issues SEO Checker

This rubric turns best practices into measurable checkpoints. In your tool, “chars” can represent URL or attribute character counts, and “pts” indicates points contributing to a 100-point score.

1) Full HTTPS Resource Coverage — 35 pts

  • - All embedded resources load via HTTPS (scripts, styles, images, fonts, media, iframes, API calls).
  • - No HTTP references found in rendered DOM or in raw HTML/CSS.
  • - Secure protocols used consistently across templates and content blocks.

2) Active Mixed Content Detection — 20 pts

  • - No HTTP JavaScript, CSS, iframe, or API endpoints.
  • - Zero browser-blocked active resources on test pages.
  • - Any detected active HTTP resource is flagged as critical.

3) Passive Mixed Content Detection — 15 pts

  • - No HTTP images, audio, or video in main content.
  • - No HTTP backgrounds in CSS.
  • - Media URLs normalize to HTTPS even in older posts.

4) Redirect & Final URL Integrity — 10 pts

  • - Resources that start on HTTPS do not redirect to HTTP.
  • - Redirect chains are short (one hop or none).
  • - No mixed protocol hops within CDN or asset hosts.

5) Template and CMS Hygiene — 10 pts

  • - Core templates and theme files contain no hardcoded HTTP assets.
  • - Site settings enforce HTTPS base URLs.
  • - Publishing editor defaults to secure embeds.

6) Ongoing Prevention Signals — 10 pts

  • - Clear trend toward stable HTTPS cleanliness over time.
  • - No recurring mixed content hotspots in specific sections.
  • - Third-party dependency list reviewed and kept secure.

Scoring Output

  • - Total: 100 pts
  • - Grade bands: 90–100 Excellent, 75–89 Strong, 60–74 Needs Attention, <60 Critical Fixes.
  • - Per-page diagnostics: Total resources scanned, count of HTTP resources, type (active/passive), resource URL length in chars, redirect chain length, and a direct fix suggestion.

Diagnostics your checker can compute

  • - Resource inventory: List every resource URL discovered per page, grouped by type.
  • - Mixed content heatmap: Show which templates or sections generate most HTTP resources.
  • - Critical alerts: Highlight active mixed content that browsers will likely block.
  • - Redirect audit: Track resources that end on HTTP even if they begin on HTTPS.
  • - Trend reporting: Compare scans over time to ensure mixed content is shrinking, not expanding.
  • - Fix queue: Prioritized list of URLs to rewrite, third-party resources to replace, and endpoints to refactor.

Workflow for maintaining an HTTPS-clean site

  1. - Scan key pages: Run the No Mixed-Content Issues Checker on homepage, top landing pages, and core templates.
  2. - Expand to full crawl: Audit all indexable pages and major content types.
  3. - Fix critical issues first: Repair active mixed content immediately to restore full functionality and trust.
  4. - Replace insecure dependencies: Remove any third-party asset that cannot serve HTTPS.
  5. - Update stored content URLs: Normalize old posts, products, and library items to HTTPS.
  6. - Recheck after updates: Confirm that fixes work in the rendered page, not only in source.
  7. - Schedule recurring audits: Keep mixed content near zero as the site evolves.

Final takeaway

Mixed content is one of the few technical issues that affects users, browsers, and search engines at the same time. It creates visible warnings, breaks secure promises, and can quietly weaken SEO through trust and engagement loss. The solution is not just “switch HTTP to HTTPS once,” but to build a system that detects and prevents insecure resources permanently. By running a No Mixed-Content Issues (All Resources via HTTPS) SEO Checker that validates every asset, flags active vulnerabilities, catches redirect leaks, and audits templates for insecure patterns, you make your site safer, cleaner, and more resilient for long-term organic growth.