HTML Rendering Modes

HTML Rendering Modes control how browsers display a webpage. There are three modes: Quirks, Standards, and Almost Standards. These depend on the DOCTYPE, and using <!DOCTYPE html> ensures modern, consistent rendering.

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What are Rendering Modes?

Browsers have different "modes" for showing pages. Modern mode = good. Old buggy mode = bad.

Three Rendering Modes:

Mode	Trigger	What it does	Should you use?
Standards Mode	`<!DOCTYPE html>` at top	Modern, correct rendering	YES
Almost Standards Mode	Old complex DOCTYPE	Mostly modern, some quirks	No
Quirks Mode	No DOCTYPE	Emulates 1990s buggy browsers	NEVER

What happens in Quirks Mode:

Box model is broken (width includes padding differently)
CSS behaves strangely
Layout looks different in every browser
Your website looks unprofessional

The Golden Rule:

1<!DOCTYPE html>

Always put this as line 1. Never forget. It triggers Standards Mode.

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HTML Rendering Modes | Quirks vs Standards Mode | DTech Innovations™