Design language comparison
Arc vs Spline
Arc runs a light-canvas system while Spline chose dark, and they pair different display families (Marlin vs Spline Sans). Beyond surface, motion divides them — Arc is subtle, Spline is expressive.
Palette · side by side
Up to 8 dominant swatches eachSide A · light
Arc
Full Page
#3139fb
brand
#000000
foreground
#fffcec
background
#ffffff
background
#696969
foreground
#210784
accent
#ff9999
accent
Side B · dark
Spline
Full Page
#ffffff
background
#000000
foreground
#191a1d
foreground
#888888
foreground
#569cd6
accent
#0062ff
accent
#ce9178
accent
#6a9955
foreground
Typography · side by side
Primary family + weight ladder + sampleSide A · light
Arc
Full Page
- Display
- Marlin Soft SQ
- Body
- Marlin
- Mono
- ABC Favorit Mono
- Weights
- 500 · 700
Sample
The quick brown fox jumps over the lazy dog.
1234567890 — Body sample renders in the captured family if your browser has it; otherwise system fallback signals the weight ladder.
Side B · dark
Spline
Full Page
- Display
- Spline Sans
- Body
- ui-monospace
- Mono
- ui-monospace
- Weights
- 400 · 500
Sample
The quick brown fox jumps over the lazy dog.
1234567890 — Body sample renders in the captured family if your browser has it; otherwise system fallback signals the weight ladder.
Spacing scale · side by side
Base unit + first 8 scale valuesSide A · light
Arc
Full Page
- Base unit
- 4 px
- Container max
- 1440 px
Side B · dark
Spline
Full Page
- Base unit
- 4 px
- Container max
- 652 px
Motion vocabulary · side by side
Level + durations + easingsSide A · light
Arc
Full Page
- Level
- subtle
- Libraries
- —
Durations
Easings
Side B · dark
Spline
Full Page
- Level
- expressive
- Libraries
- —
Durations
Easings
Palette & spacing overlap
Their palettes share 22% of swatches at the dominant tier — a quiet signal both teams drew from the same neutral library before applying brand accents. Their spacing scales overlap by 67% (4, 6, 8, 10, 12 px shared) — a rhythm any agent can transfer between the two systems with minimal recalibration.
Shared swatches (2)
Curator verdict
Pick a side. Mixing Arc's light-first canvas with Spline's expressive motion vocabulary produces visual whiplash. Adopt one system as your primary, study the other for individual technique transfers (e.g. Arc's spacing, Spline's shadow).