Emoji & 4-Byte Character Checker

Why emoji turn into ??? in Magento

Text is stored as UTF-8, where each character takes 1 to 4 bytes. MySQL's older utf8 character set (now called utf8mb3) only stores characters up to 3 bytes. Most emoji, and the "fancy" bold and italic letters that font-changer sites produce, need 4. Older Magento installs created many tables with utf8mb3, so those characters come out as ?, or the text is cut off at the first one, often without any error in the admin.

Not every emoji is a problem. Older symbols such as ❤ ✔ ★ and ☀ are only 3 bytes and store fine; the checker lists any it finds as safe.

Check your own database

Run this in your Magento database (for example in phpMyAdmin or the mysql command line). Any rows it returns are columns that still can't store emoji:

SELECT TABLE_NAME, COLUMN_NAME, CHARACTER_SET_NAME
FROM information_schema.COLUMNS
WHERE TABLE_SCHEMA = DATABASE()
  AND CHARACTER_SET_NAME IN ('utf8', 'utf8mb3')
  AND TABLE_NAME IN ('catalog_product_entity_varchar', 'catalog_product_entity_text',
                     'catalog_category_entity_varchar', 'catalog_category_entity_text',
                     'cms_page', 'cms_block', 'review_detail', 'sales_order_address',
                     'customer_entity', 'customer_address_entity')
ORDER BY TABLE_NAME, COLUMN_NAME;

If you use a table prefix, add it to the table names.

Fixing it for good

The columns need converting to utf8mb4. On MySQL 8.4 or later (or a modern MariaDB), Magento keeps them on utf8mb4 once converted. On older MySQL, every setup:upgrade can quietly convert them back, so upgrade the database first.