Magento 2 mixed content – HTTP resources blocked on HTTPS page

After moving the shop to HTTPS, product images and CSS stylesheets stopped loading in Chrome. The console showed hundreds of Mixed Content errors. The shop looked broken. Fix time: 1 hour.

Symptoms

• After HTTPS migration: no CSS styles and missing product images
• Browser console: Mixed Content: The page was loaded over HTTPS but requested an insecure resource over HTTP
• Media URLs in the database contain http:// instead of https://

Solution

bin/magento config:set web/unsecure/base_url https://shop.com/
bin/magento config:set web/secure/base_url https://shop.com/
bin/magento config:set web/secure/use_in_frontend 1
bin/magento config:set web/secure/use_in_adminhtml 1

UPDATE core_config_data
SET value = REPLACE(value, 'http://shop.com', 'https://shop.com')
WHERE value LIKE '%http://shop.com%';

bin/magento cache:flush
bin/magento setup:static-content:deploy -f

Takeaways

HTTPS migration requires updating URLs in the database, Magento configuration and checking redirects. Nginx should automatically redirect HTTP to HTTPS via return 301 https://....