AssemblyAI — design system & UI screens

AI · 1 screen · 9 sections · https://www.assemblyai.com/

Light developer landing; a serif headline beside trust copy over a real-time speech-to-text API UI mockup with mode tabs (Realtime, Pre-recorded, Voice Agent).

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/website/assemblyai.

Decoded design system

AssemblyAI's decoded design system: background #FDFCF8, text #1D1B16, accent #3923C7, link #C7C3B2, primary #3923C7; type scale h1 72px / h2 64px / body 12px; 8px spacing base; 0px base radius. The single interactive/action color is #3923C7 — used only on interactive or must-notice elements (buttons, links, key highlights), never on large fills.

Color roles

Role	Value
bg	`#FDFCF8`
surface	`#EFEEEA`
border	`#DBDAD6`
text	`#1D1B16`
text_muted	`#72706B`
primary	`#3923C7`
accent	`#3923C7`
link	`#C7C3B2`
button_bg	`#3923C7`
button_text	`#FFFFFF`

Using these colors

Action color #3923C7 — the single interactive color; only on things you click or must notice, never large fills.
primary, accent, button_bg are all #3923C7 — one role, not several (the action color).
accent #3923C7 — THE accent / action color — interactive & must-notice only (buttons, links, focus, one key highlight); never large fills or backgrounds. Scarcity is what makes it read as designed.
link #C7C3B2 — fails contrast on the background (~1.7:1) — this is a dark UI color, NOT a readable link; use the text or action color for links (verify against the reference).

Typography

Heading: Georgia
Body: Georgia
Mono: Modern Gothic Mono
h1: 72px
h2: 64px
body: 12px

Spacing

base unit: 8px
scale: 4px, 8px, 10px, 12px, 16px, 24px, 30px, 32px, 48px, 80px

Radii

base: 0px
button: 2px

Shadows (elevation)

card: rgba(0, 0, 0, 0.2) 0px 0px 18px 0px

Motion

Micro-interactions run at 150ms (dominant) with cubic-bezier(0.4, 0, 0.2, 1).

durations: 150ms · 200ms · 500ms
easings: cubic-bezier(0.4, 0, 0.2, 1) · ease
animated properties: color, outline-color, background-color, border-color

Native design tokens

Token	Value
`--color-black-500`	`#1d1b16`
`--color-neutral-300`	`#c7c3b2`
`--color-cobolt-500`	`#3923c7`
`--color-green-100`	`#cee0d4`
`--color-neutral-200`	`#dad7cb`
`--color-green-500`	`#01762f`
`--color-white`	`#fff`
`--color-blush-300`	`#ec9d92`
`--color-black-300`	`#777673`
`--color-gray-100`	`oklch(96.7% .003 264.542)`

…and 87 more measured on the page.

Button states (measured)

primary hover: background #887BDD
primary focus: outline 1px auto rgb(16, 16, 16)

Layout (measured)

container max-width: 1440px
common grid: 2 columns

Motion choreography (measured)

Load order: div.flex → div.onetrust-pc-dark-filter

Scroll reveal: 2 elements rest at opacity 0, animate in over 0.5s cubic-bezier(0.4, 0, 0.2, 1).

Overlay recipe (measured)

dialog panel: rgba(0, 0, 0, 0) · radius 0px

Responsive (measured)

breakpoints: 425px · 550px · 600px · 640px · 768px · 896px
mobile (390px): hero 40px · nav hamburger

Full design system, per-section tokens & DESIGN.md / Tailwind / CSS exports →

Screens

AssemblyAI - Voice AI Infrastructure for Builders