DOM Performance

How the browser renders the document
- Receives the data (bytes) from the server.
- Parses and converts into tokens (<, TagName, Attribute, AttributeValue, >).
- Turns tokens into nodes.
- Turns nodes into the DOM tree.
Builds CSSOM tree from the css rules.

vishnumohanan404 / what-forces-layout.md

Created November 27, 2021 11:12 — forked from paulirish/what-forces-layout.md

What forces layout/reflow. The comprehensive list.

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

vishnumohanan404 / css-units-best-practices.md

Created July 9, 2021 06:18 — forked from basham/css-units-best-practices.md

CSS Units Best Practices

CSS units

Recommendations of unit types per media type:

Media	Recommended	Occasional use	Infrequent use	Not recommended
Screen	em, rem, %	px	ch, ex, vw, vh, vmin, vmax	cm, mm, in, pt, pc
Print	em, rem, %	cm, mm, in, pt, pc	ch, ex	px, vw, vh, vmin, vmax

Relative units