---
id: css-image-hover
title: "CSS Image Hover Overlays"
category: "Frontend"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["image overlay", "hover overlay", "fade overlay", "slide overlay", "image hover effect"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.85
created_at: 2026-06-23
updated_at: 2026-06-23
review_reason: ""
merge_history: []
tags: ["css", "web", "frontend", "w3schools", "images", "hover"]
raw_sources: ["https://www.w3schools.com/css/css3_images_hover.asp"]
applied_in: []
github_commit: ""
---

# [[CSS Image Hover Overlays]]

## 🎯 한 줄 통찰 (One-line insight)
A hover overlay reveals hidden content over an image when the user hovers, either fading in (text or a box) or sliding in from the top, bottom, left, or right. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Overlay on hover** — the goal is to create an overlay effect on hover that reveals text or a colored box over the image. [S1]
- **Fade effects** — the overlay can fade in text, or fade in a box, when the image is hovered. [S1]
- **Slide effects** — the overlay can also slide in from the top, bottom, left, or right. [S1]
- **Reveal mechanism** — the overlay element starts hidden (typically `opacity: 0` or zero size) and a hover rule reveals it, with a `transition` for smoothness. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **Hidden-then-revealed overlay** — place an overlay element over the image, keep it hidden, and flip it on the container's `:hover`. [S1]
- **Direction by initial offset** — slide effects differ by which dimension/offset starts collapsed (top/bottom/left/right) and grows on hover. [S1]

## 📖 세부 내용 (Details)
**Overlay image hover effects**
The page demonstrates how to create an overlay effect on hover, revealing hidden content or a visual enhancement over an image. The examples, in order, are: [S1]

1. Fade in text
2. Fade in a box
3. Slide in (top)
4. Slide in (bottom)
5. Slide in (left)
6. Slide in (right)

**Implementation pattern (described)**
The overlay pattern uses an overlay element with an initial `opacity` of `0` (invisible), a `transition` property for a smooth reveal, a `background-color` for the overlay layer, and a hover state that changes `opacity` to `1` (or adjusts dimensions for slide effects). [S1]

**Code availability**
The detailed CSS for the `.container`, `.image`, `.overlay`, and `.text` classes — including the exact transition durations, opacity values, and positioning — is presented on the page only as "Try it Yourself" interactive examples and is **Not found in source** as inline code in the fetched content. The exact declaration blocks should not be invented; consult the W3Schools editor for verbatim code. [S1]

## 🛠️ 적용 사례 (Applied in summary)
The source's applied cases are the six hover-overlay demos (fade-in text, fade-in box, and four slide-in directions). The exact CSS for each is not reproduced here (Not found in source). No external project/commit applications found in the source.

## 💻 코드 패턴 (Code patterns)
Conceptual overlay-reveal skeleton, grounded in the page's described pattern (exact W3Schools values Not found in source):
```css
.overlay {
  opacity: 0;
  transition: opacity 0.5s;
  background-color: /* overlay color */;
}

.container:hover .overlay {
  opacity: 1;
}
```

## ⚖️ 비교 및 선택 기준 (Comparison & decision criteria)
Per the source, choose **fade** effects (text or box) when you want the overlay to appear in place, and **slide** effects when you want it to enter from an edge; the four slide directions (top, bottom, left, right) differ only by which edge the overlay starts collapsed against and grows from on hover. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
No contradictions found in the source. Note: full per-example CSS was not available inline (marked "Not found in source").

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual (실제 적용 사례 발견 시 applied/validated로 승격 가능)
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.85
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[CSS Tutorial]]
- **관련 개념:** [[CSS Image Effects]], [[CSS Image Modal]], [[CSS Transitions]], [[CSS Opacity]]
- **참조 맥락:** Referenced when adding interactive captions or reveal effects to images in galleries and cards.

## 📚 출처 (Sources)
- [S1] W3Schools — CSS Image Hover Overlays — https://www.w3schools.com/css/css3_images_hover.asp

## 📝 변경 이력 (Change history)
- 2026-06-23: Initial draft synthesized from the W3Schools "CSS Image Hover Overlays" page (Astra wiki-curation, P-Reinforce v3.1 format).
