# Intersection Observer API
Status: public
Confidence: medium (0.855) (verified)
Last verified: 2026-05-28
Generation: human_only

## TL;DR
The Intersection Observer API lets code observe when elements enter or leave a viewport or scrolling container. It is commonly used for lazy loading, infinite scrolling, and visibility tracking.

## Core Explanation
Instead of polling scroll positions, developers register observers and receive callbacks when intersection thresholds are crossed.

## Detailed Analysis
This repair cites MDN, the W3C specification, and web.dev for API behavior and common use cases.

## Related Articles

- [API Gateway](../api-gateway.md)
- [Broadcast Channel API](../broadcast-channel-api.md)
- [Canvas API](../canvas-api.md)