---
id: kb-2026-00166
title: CSS Flexbox
schema_type: TechArticle
category: computer-science
language: en
confidence: medium
last_verified: '2026-05-28'
created_date: '2026-05-22'
generation_method: human_only
derived_from_human_seed: true
conflict_of_interest: none_declared
is_live_document: false
data_period: static
atomic_facts:
  - id: fact-computer-science-001
    statement: >-
      The W3C Flexbox specification defines a CSS box model optimized for user-interface layout in
      one dimension.
    source_title: CSS Flexible Box Layout Module Level 1
    source_url: https://www.w3.org/TR/css-flexbox-1/
    confidence: medium
  - id: fact-computer-science-002
    statement: MDN explains flexbox using a main axis and a cross axis.
    source_title: Basic concepts of flexbox - CSS | MDN
    source_url: >-
      https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_flexible_box_layout/Basic_concepts_of_flexbox
    confidence: medium
  - id: fact-computer-science-003
    statement: web.dev teaches flexbox as a layout model for distributing space and aligning items.
    source_title: 'Learn CSS: Flexbox'
    source_url: https://web.dev/learn/css/flexbox
    confidence: medium
completeness: 0.88
known_gaps:
  - >-
    Coverage intentionally narrowed to directly sourced public evidence; adjacent subtopics are not
    exhaustively covered.
disputed_statements: []
primary_sources:
  - title: CSS Flexible Box Layout Module Level 1
    type: standard
    year: 2018
    url: https://www.w3.org/TR/css-flexbox-1/
    institution: W3C
  - title: Basic concepts of flexbox - CSS | MDN
    type: documentation
    year: 2025
    url: >-
      https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_flexible_box_layout/Basic_concepts_of_flexbox
    institution: Mozilla
  - title: 'Learn CSS: Flexbox'
    type: documentation
    year: 2025
    url: https://web.dev/learn/css/flexbox
    institution: Google
secondary_sources: []
updated: '2026-05-28'
---
## TL;DR

CSS Flexbox is a one-dimensional layout model for arranging items in a row or column. This repair removes duplicates and keeps claims to W3C, MDN, and web.dev documentation.

## Core Explanation

Flexbox centers on a flex container and flex items. It distributes space along a main axis and aligns content along a cross axis, which makes it useful for navigation, controls, and component layout.

## Further Reading

- [CSS Flexible Box Layout Module Level 1](https://www.w3.org/TR/css-flexbox-1/)
- [Basic concepts of flexbox - CSS | MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_flexible_box_layout/Basic_concepts_of_flexbox)
- [Learn CSS: Flexbox](https://web.dev/learn/css/flexbox)

## Related Articles

- [CSS Grid](../css-grid.md)
- [CSS (Cascading Style Sheets)](../css.md)