CHECK GLOSSARY · RENDER-001

Render-blocking scripts

In plain words: Scripts in the head without async or defer stop the page from showing until they finish downloading.

How to fix it

Add defer or async to scripts in the head.

Official sources

• web.dev: render-blocking

Related checks

• DOM-001: Very large page structure
• REFRESH-001: Meta refresh redirect
• SOCIAL-002: Missing Twitter/X card tag
• SOCIAL-003: Incomplete Open Graph tags

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