.sketch

What is a .sketch file?

Sketch is a macOS-only UI/UX design file format — containing artboards, symbols, and vector artwork for interface design.

Safe format
Type Image
By Sketch B.V.
MIME application/zip

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What is it

You received a .sketch file — the native format for Sketch, a UI/UX design tool that was the industry standard before Figma went cloud-first and ate its market share. Sketch files contain artboards, symbols, shared styles, and vector artwork for interface design, icon sets, and web layouts.

Sketch is macOS-only, which was always its strategic weakness. When Figma arrived with browser-based, cross-platform, real-time collaboration, many design teams migrated. Sketch responded with its own collaboration features, but the damage was done. Sketch files remain common in existing design systems, handoff documentation, and teams that prefer native Mac performance over browser-based tools.

Sketch (macOS, subscription or one-time purchase) opens .sketch natively. Figma can import Sketch files with good fidelity — it's a common migration path. Lunacy (free, Windows/macOS/Linux) opens and edits Sketch files without a Mac. For developers receiving Sketch files for implementation, Zeplin and Avocode provide design-to-code handoff without needing Sketch installed.

Technical details
Full Name
Sketch Design File
MIME Type
application/zip
Developer
Sketch B.V.
Magic Bytes
50 4B 03 04
Safety
.sketch is a known, safe format.
What opens it
Sketch
$120/year macOS
Figma (import)
FREE Web
Lunacy
FREE All
FAQ
Can I open a Sketch file on Windows?
Lunacy (free, by Icons8) opens and edits Sketch files on Windows, macOS, and Linux. Figma can import Sketch files via the web. You don't need a Mac to view or work with Sketch designs.
Should I use Sketch or Figma?
Figma for collaboration and cross-platform teams. Sketch for Mac-only teams who prefer native performance. Figma's free tier is generous; Sketch requires a license. Most new design teams choose Figma. Many established teams still use Sketch effectively.
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