---
id: css-outline-width
title: "CSS Outline Width"
category: "Frontend"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["outline-width", "CSS outline width", "thin medium thick outline", "outline size", "outline thickness"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.88
created_at: 2026-06-23
updated_at: 2026-06-23
review_reason: ""
merge_history: []
tags: ["css", "web", "frontend", "w3schools", "outline", "outline-width"]
raw_sources: ["https://www.w3schools.com/css/css_outline_width.asp"]
applied_in: []
github_commit: ""
---

# [[CSS Outline Width]]

## 🎯 한 줄 통찰 (One-line insight)
The `outline-width` property specifies the width of an outline, set either as a keyword (`thin`, `medium`, `thick`) or as a specific size. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Purpose** — the `outline-width` property specifies the width (thickness) of an outline. [S1]
- **Keyword values** — `thin` (typically 1px), `medium` (typically 3px), and `thick` (typically 5px). [S1]
- **Explicit size** — a specific size in px, pt, cm, em, etc. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **Keyword vs. explicit** — use `thin`/`medium`/`thick` for quick relative sizing, or a length unit when an exact thickness is required. [S1]
- **Requires a style** — `outline-width` is only visible alongside a set `outline-style` (e.g., `solid`). [S1]

## 📖 세부 내용 (Details)
**Accepted values**
The `outline-width` property specifies the outline's dimensions with these accepted values: [S1]
- `thin` (typically 1px)
- `medium` (typically 3px)
- `thick` (typically 5px)
- a specific size in px, pt, cm, em, etc.

**Demo example** — demonstration of different outline widths, each class applying a different `outline-width` value to paragraphs styled with solid green outlines and 5px padding: [S1]
```css
p {
  padding: 5px;
  outline-style: solid;
  outline-color: green;
}

p.ex1 {
  outline-width: thin;
}

p.ex2 {
  outline-width: medium;
}

p.ex3 {
  outline-width: thick;
}

p.ex4 {
  outline-width: 8px;
}
```

## 🛠️ 적용 사례 (Applied in summary)
The four-class demo above is the page's own applied example, showing `thin`, `medium`, `thick`, and an explicit `8px` outline. No external project/commit applications found in the source.

## 💻 코드 패턴 (Code patterns)
Set outline width by keyword or length (language: CSS):
```css
p.ex2 {
  outline-style: solid;
  outline-width: medium;
}

p.ex4 {
  outline-style: solid;
  outline-width: 8px;
}
```

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
No contradictions found in the 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:** 0.88
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[CSS Tutorial]]
- **관련 개념:** [[CSS Outline Style]], [[CSS Outline Color]], [[CSS Box Model]]
- **참조 맥락:** Referenced when adjusting the thickness of an element's outline.

## 📚 출처 (Sources)
- [S1] W3Schools — CSS Outline Width — https://www.w3schools.com/css/css_outline_width.asp

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