Indeterminate Linear Progress

A bar fills from left to right in proportion to task completion.

Add a "Determinate Progress Bar" (also called a progress bar fill or progress indicator) to [where].
The bar should fill from left to right in step with the real progress, easing smoothly between updates, with the percentage shown beside it.
Use proper progress bar semantics with current, minimum and maximum values so screen readers can read it, and never let the fill move backwards.

A thin bar at the top of the page creeps forward during navigation and finishes on load.

Add a "Top Loading Bar" (also called a page progress bar) to [where].
A thin bar along the top edge should dart forward at first and then creep more and more slowly while the page loads; when loading finishes it should race to the end and fade out.
Never let it reach the end before loading is actually done, and keep it from covering or shifting the page content.

Gray placeholder shapes show a light highlight sweeping across them.

Add a "Skeleton Shimmer" (also called a skeleton wave or shimmer effect) to [where].
A soft band of light should sweep across the gray placeholder shapes from left to right and pause briefly before the next pass: smooth and unhurried.
Match the placeholder shapes to the real layout so nothing jumps when the content loads, and show static placeholders to users who prefer reduced motion.

A list of steps highlights or checks off one by one as a long task advances.

Add a "Multi-Step Loader" (also called a step loader or checklist loader) to [where].
The steps should light up one at a time from top to bottom, and each should get a small checkmark that pops in as it completes, at a calm, readable pace.
Advance the steps with the real task progress rather than a fixed timer, and announce each completed step to screen readers.

A circular arc grows around a ring to show percentage complete.

Add a "Progress Ring" (also called circular progress or radial progress) to [where].
Starting at the top, an arc should grow clockwise around the ring to show the percentage complete, easing out as it settles, while the number in the center counts up alongside it.
Keep the arc and the number in sync, and expose the value with proper progress bar semantics for screen readers.

Gray placeholder blocks fade in and out gently to signal loading.

Add a "Pulse Placeholder" (also called a skeleton pulse) to [where].
Gray placeholder blocks shaped like the coming content should slowly fade lighter and back together in a gentle, steady rhythm.
Match the placeholders to the real layout so nothing jumps when the content arrives, and keep them still for users who prefer reduced motion.