Remediation Guide 9 min read

How to Fix Mixed Content

Use this page when the Mixed Content Checker finds HTTP asset references on HTTPS pages.

What This Means

Mixed content is usually a cleanup problem left behind after HTTPS migration, theme changes, or CDN rewrites. The safest fix order is to remove active-content issues first because they carry the highest security impact, then work through passive assets and stale hardcoded references.

Asset typeWhat to verifyWhy it matters
ScriptsAny HTTP script or injected third-party assetActive mixed content can directly weaken execution trust.
StylesheetsHardcoded HTTP CSS or font loadsThese still degrade browser security and consistency.
Images and mediaPassive HTTP assets after migrationLower risk than scripts, but still noisy and trust-reducing.
Generated contentCMS, theme, or build-time asset URLsThese often keep reintroducing the same problem.

Common Causes

Patterns worth checking first

  • Incomplete migration: Templates or CMS content still reference old HTTP asset URLs.
  • Third-party dependencies: A vendor script or widget still loads insecure subresources.
  • Rewrite gaps: CDN or proxy rules did not normalize every asset path consistently.

How To Confirm It Safely

Confirmation steps

  • Identify whether the issue affects scripts, styles, images, or generated content.
  • Check whether the insecure URL is hardcoded, CMS-managed, or third-party controlled.
  • Confirm whether the asset is still needed before rewriting it.
  • Capture the public page path where the issue is observed for rerun validation.

Fix Workflow

  1. Remove active mixed content first. Prioritize scripts and other high-risk assets before passive content cleanup.
  2. Replace stale URLs at the source. Fix templates, CMS content, or build logic so the issue does not reappear.
  3. Update or remove third-party dependencies. Require HTTPS-only asset loading from external providers.
  4. Retest the public page. Confirm the insecure references are gone from the live HTTPS response.

Implementation Examples

Protocol-safe asset replacement
https://cdn.example.com/app.js

Rollout Risks

Quick search-and-replace can miss CMS or generated asset sources

The visible page is often assembled from multiple content sources.

  • Fix the generator, not only the output.
  • Retest the rendered public page after each change.
Third-party assets can regress after vendor updates

A provider may still serve or reference insecure resources later.

  • Review vendor documentation.
  • Monitor high-risk pages after the initial cleanup.

Validation Checklist

Post-fix validation

  • Active mixed-content issues are removed from public HTTPS pages.
  • Passive insecure assets are reduced or eliminated where practical.
  • The source of the insecure reference was fixed, not only the symptom.
  • The Mixed Content Checker confirms the cleaner asset profile.

FAQ

Are images as urgent as scripts?

Usually no. Active content carries higher direct risk than passive media.

  • Prioritize scripts and styles first.
  • Still clean up passive assets for trust and consistency.
Can a CDN rewrite solve everything?

It can help, but stale source references often still need cleanup.

  • Use rewrites as support, not the only fix.
  • Correct the template or content source too.