Duolingo — decoded design system

duolingo.com · light · playful · custom · deep decode — measured live

Duolingo's design system, decoded live by Mozaika: measured color roles, type scale, buttons with real hover/focus states, motion and the brand's own tokens.

Open in Mozaika →

This is a static, crawlable rendering for search & AI engines. The interactive version — filters, live decode console, copy & export — is at https://mozaika.design/decode/duolingo.com.

Decoded design system

Duolingo's decoded design system: background #FFFFFF, text #3C3C3C, accent #100F3E, link #A5ED6E, primary #1CB0F6; type scale h1 64px / h2 48px / body 17px; 4px spacing base; 3px base radius. The single interactive/action color is #1CB0F6 — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

Using these colors

• Action color #1CB0F6 — the single interactive color; only on things you click or must notice, never large fills.
• primary, button_bg are all #1CB0F6 — one role, not several (the action color).
• accent #100F3E — accent for emphasis — keep it rare on the page.
• link #A5ED6E — fails contrast on the background (~1.4:1) — this is a dark UI color, NOT a readable link; use the text or action color for links (verify against the reference).
• secondary #0000EE — optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two.

Typography

• Heading: Duolingo Sans
• Body: Duolingo Sans
• h1: 64px
• h2: 48px
• body: 17px

Spacing

• base unit: 4px
• scale: 12px, 16px, 23px, 24px, 30px, 40px, 48px, 70px, 80px, 96px

Radii

• base: 3px
• button: 12px

Motion

Micro-interactions run at 200ms (dominant) with ease.

• durations: 200ms · 300ms · 400ms
• easings: ease · cubic-bezier(0.22, 1, 0.36, 1)
• animated properties: transform, border-color, filter

Native design tokens

…and 29 more measured on the page.

Layout (measured)

• container max-width: 990px
• nav: 900px
• common grid: 2 columns

Motion choreography (measured)

Scroll reveal: 3 elements rest at opacity 0, animate in over 400ms.

Responsive (measured)

• breakpoints: 530px · 550px · 699px · 768px · 896px · 1065px
• mobile (390px): hero 32px · nav hamburger

Install it

Drop this measured system into any shadcn/Tailwind project in one command:

npx shadcn add mozaika.design/r/decode/duolingo.com

registry item · or query it over MCP: get_design_system("Duolingo")

Export: DESIGN.md

# Duolingo — Design System

> light, playful, high, custom — deep decode (measured live)

## Colors

| Role | Value |
|------|-------|
| bg | `#FFFFFF` |
| surface | `#F3F3F3` |
| border | `#E1E1E1` |
| text | `#3C3C3C` |
| text_muted | `#868686` |
| primary | `#1CB0F6` |
| accent | `#100F3E` |
| link | `#A5ED6E` |
| secondary | `#0000EE` |
| button_bg | `#1CB0F6` |
| button_text | `#FFFFFF` |

**Using these colors**

- **Action color** `#1CB0F6` — the single interactive color; it appears only on things you click or must notice (buttons, key highlights), never on large fills or backgrounds.
- `primary`, `button_bg` are all `#1CB0F6` — one role, not several (your action color).
- **accent** `#100F3E` — accent for emphasis — keep it rare on the page.
- **link** `#A5ED6E` — fails contrast on the background (~1.4:1) — this is a dark UI color, NOT a readable link; use the text or action color for links (verify against the reference).
- **secondary** `#0000EE` — optional secondary accent — LOW decode confidence; use rarely (a status color or a single decorative moment) or omit it entirely. Prefer one accent unless the reference clearly shows two.
- **Page coverage** (full-page screenshot pixels): `#FFFFFF` 89.3% · `#23B3EC` 2.6% · `#5ACF1B` 2.5% · `#BEDFC2` 1.7% — the action color covers ~2.6% of the page; keep it that scarce.

## Typography

- Heading: **Duolingo Sans** _(free fallback: Newsreader)_
- Body: **Duolingo Sans** _(free fallback: Newsreader)_

| Role | Size / weight · line-height · tracking |
|------|------------------------------------------|
| hero | 64px / 700 · tracking -1.28px |
| h2 | 48px / 700 |
| h3 | 32px / 700 |
| body | 17px / 500 · lh 24px |
| small | 15px / 700 · lh 20px · tracking 0.8px |
| eyebrow | 15px / 700 · tracking 0.8px |

- Weight ladder: 400 · 500 · 600 · 700 — use these exact measured weights, not the 400/600 defaults.

> **Fonts —** Duolingo Sans may be proprietary — safe free fallback: Newsreader (Google Fonts).

## Spacing
- base unit: 4px (inferred from the measured scale)
- measured scale: 12px, 16px, 23px, 24px, 30px, 40px, 48px, 70px, 80px, 96px — snap all gaps/padding to these
- section rhythm: 96px top/bottom padding per section (measured)

## Radius
- base: 3px
- button: 12px
- card: 12px
- sharp: 2px

## Buttons

| Button | Fill / text | Border | Radius | Padding | Font | Shadow |
|--------|-------------|--------|--------|---------|------|--------|
| primary | `#1CB0F6` / `#FFFFFF` | none | 12px | 13px 16px 13px 16px | 700 15px / 0.8px | none |
| secondary | `rgba(0, 0, 0, 0)` / `#FFFFFF` | none | 12px | 0px 16px 0px 16px | 700 15px / 0.8px | none |

## Motion
- durations: 200ms (dominant) · 300ms · 400ms
- easings: `ease` (dominant) · `cubic-bezier(0.22, 1, 0.36, 1)`
- animated properties: transform, border-color, filter

Micro-interactions use the dominant duration + easing; nothing on the page animates slower than the longest duration above — don't invent springier motion.

## Their own tokens (verbatim from :root)

| Token | Value |
|-------|-------|
| `--web-ui_button-border-radius` | `16px` |
| `--text-heading-weight-medium` | `700` |
| `--text-label-weight-large` | `700` |
| `--text-heading-weight-xsmall` | `700` |
| `--text-heading-weight-small` | `700` |
| `--text-body-weight-bold` | `700` |
| `--text-caption-weight-bold` | `700` |
| `--text-body-weight-spacious-bold` | `700` |
| `--text-body-weight-spacious` | `500` |
| `--text-label-weight-medium` | `700` |
| `--text-pageTitle-weight-large` | `700` |
| `--text-heading-weight-large` | `700` |

_…and 27 more measured on the page._

Prefer these names when extending their system — it's the brand's actual vocabulary.

## Layout (measured)
- container max 990px · common grid: 2-col
- nav: 900px

| Section (y) | Height | Cols | Gap | Pad y | Split |
|---|---|---|---|---|---|
| 996 | 530 | 2 | 101 | 0/0 | — |
| 1526 | 530 | 2 | 101 | 0/0 | — |
| 2056 | 530 | 2 | 101 | 0/0 | — |
| 2586 | 530 | 2 | 101 | 0/0 | — |
| 3212 | 1289 | — | — | 0/0 | — |
| 4501 | 900 | 2 | 40 | 0/0 | — |

## Motion choreography (measured)
- `div._1ATOC` ×2 — opacity 1→0 — 300ms ease
- scroll reveal: 3 elements rest at opacity 0, animate in over 400ms (0 revealed during the drive).

Rebuild the timeline, not just the durations — order, delays and staggers above are the choreography.

## Components (measured)
- link: #1CB0F6 · no underline

## Responsive (measured)
- breakpoints: 530px · 550px · 699px · 768px · 896px · 1065px
- mobile (390px): hero 32px · body 17px · nav: hamburger

## How to apply
Paste the Tailwind `@theme` (or CSS variables) as your base, then build each
section to its spec — verify every color, radius, and font against these tokens.
Hover/focus states, shadows and motion timings above are measured from the live page — match them exactly, don't re-guess them.

← All decoded design systems

An automated reading of Duolingo's publicly-visible CSS (colors, fonts, spacing, motion) — not affiliated with duolingo.com. No screenshots stored. Removal requests: hello@mozaika.design.