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slang.fyi

mobile-first

/ˈmoʊbəl fɜːrst/

Common

Design and build for small screens before scaling up to larger ones.

Both a design philosophy and a CSS technique. In CSS it means using min-width media queries. As a philosophy it means mobile users get the core experience, not a stripped-down version.

Real-world examples4 examples
#ExampleWhat it meansSource
01we're going mobile-first on this redesign. desktop gets the extrasThe mobile layout is the baseline and desktop adds features on top.x, 2023
02always write mobile-first CSS. max-width queries are a trapThe speaker prefers min-width media queries starting from mobile rather than max-width from desktop.x, 2024
03our users are 80% mobile. if you're not building mobile-first you're building wrongThe speaker argues mobile-first is not optional when most users are on phones.reddit, 2023
04figma file is desktop. now I have to design mobile-first in my headThe design was created in desktop view and the developer has to mentally reverse-engineer the mobile layout.x, 2024

Use it when

  • You are describing a design approach that prioritizes mobile screens.
  • You start writing CSS for small screens and add breakpoints going up.
  • A product team puts mobile users at the center of design decisions.

Do not use it when

  • You just mean the app has a mobile version.
  • You mean the site is responsive.Use “responsive-design” instead.

Mobile-first vs responsive design

mobile-first

Mobile-first is the methodology: design from smallest to largest.

VS

responsive-design

Responsive design is the outcome: a layout that works at any size.

Origin and context

Popularized by designer Luke Wroblewski in his 2009 article and 2011 book of the same name. He argued that designing for mobile constraints first produced better overall products.

First seen
2009
Confidence
high

Cite this page

Use this stable URL to reference the entry.

https://slang.fyi/mobile-first
Updated: 2026-08-28License: CC BY 4.0

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