What is SKETCH?

SKETCH files are Sketch app's native design format - actually ZIP archives containing JSON data and embedded images. Structure includes: pages.json (artboard layouts), layers.json (vector shapes), images/ folder (embedded bitmaps), and metadata.json. Sketch pioneered the modern UI/UX design workflow with symbols (reusable components), shared styles, and plugin ecosystem. Uses native macOS rendering for crisp vector graphics. Files can be unzipped to inspect/edit JSON directly.

Sketch dominated digital design from 2014-2018 before Figma's rise. Still widely used, particularly by Mac-centric design teams and agencies. Popular for iOS/macOS app design due to native Apple ecosystem integration. Extensive plugin ecosystem (Sketch Runner, Anima, Abstract). Sketch Cloud enables collaboration (browser preview, commenting). Many design systems and UI kits distributed as .sketch files. macOS-only limitation led to Figma's cross-platform advantage. Still preferred by designers who value local files and offline work.

Did you know? Sketch files are ZIP archives - rename to .zip to explore the JSON structure!

History

Bohemian Coding created Sketch as a lightweight alternative to Adobe Photoshop for UI design, revolutionizing digital product design workflows.

Key Milestones

  • 2010: Sketch 1.0 launched
  • 2014: Symbols introduced (v3.0)
  • 2016: Industry standard for UI/UX
  • 2017: Sketch Cloud collaboration
  • 2019: Subscription model introduced
  • Present: Facing Figma competition

Key Features

Core Capabilities

  • Vector Editing: Native macOS rendering
  • Symbols: Reusable components
  • Shared Styles: Design tokens
  • Artboards: Multiple screen sizes
  • Plugins: Extensive ecosystem
  • Prototyping: Link artboards

Common Use Cases

iOS Design

Native app interfaces

Web UI

Website mockups

Icon Design

Vector icon sets

Design Systems

Component libraries

Advantages

  • Native macOS performance
  • Local files (offline work)
  • Extensive plugin ecosystem
  • Clean, focused interface
  • Excellent vector tools
  • ZIP-based (inspectable format)
  • Strong iOS design community

Disadvantages

  • macOS-only (no Windows/Linux)
  • Limited real-time collaboration
  • Losing market share to Figma
  • Subscription pricing
  • Sketch Cloud less robust than Figma
  • Version control challenges

Technical Information

Format Specifications

Specification Details
File Extension .sketch
MIME Type application/x-sketch
Base Format ZIP archive
Contents JSON + embedded images
Platform macOS only
Export PNG, JPG, SVG, PDF

Common Tools

  • Primary: Sketch app (macOS only)
  • Collaboration: Sketch Cloud (browser preview)
  • Version Control: Abstract, Kactus, Plant
  • Conversion: Figma import, Lunacy (Windows viewer)