Design language comparison
Cal.com vs PostHog
Both Cal.com and PostHog commit to a light-canvas approach, and they pair different display families (sans-serif vs Open Runde). Beyond surface, motion divides them — Cal.com is moderate, PostHog is expressive.
Palette · side by side
Up to 8 dominant swatches eachSide A · light
Cal.com
Full Page
#000000
foreground
#242424
foreground
#898989
background
#ffffff
background
#0000ee
accent
#e0e0e0
background
#e5e7eb
background
#374151
foreground
Side B · light
PostHog
Full Page
#4d4f46
foreground
#000000
foreground
#374151
foreground
#9ea096
neutral
#111827
foreground
#65675e
foreground
#f7a501
accent
#bfc1b7
neutral
Typography · side by side
Primary family + weight ladder + sampleSide A · light
Cal.com
Full Page
- Display
- Cal Sans UI Variable Light
- Body
- sans-serif
- Weights
- 300
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 · light
PostHog
Full Page
- Display
- Open Runde
- Body
- IBM Plex Sans Variable
- Mono
- ui-monospace
- Weights
- 400 · 500 · 600 · 700 · 800
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
Cal.com
Full Page
- Base unit
- 4 px
- Container max
- 1280 px
Side B · light
PostHog
Full Page
- Base unit
- 4 px
- Container max
- 320 px
Motion vocabulary · side by side
Level + durations + easingsSide A · light
Cal.com
Full Page
- Level
- moderate
- Libraries
- Framer Motion
Durations
Easings
Side B · light
PostHog
Full Page
- Level
- expressive
- Libraries
- —
Durations
Easings
Palette & spacing overlap
Their palettes share 15% 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 75% (2, 4, 6, 8, 10 px shared) — a rhythm any agent can transfer between the two systems with minimal recalibration.
Shared swatches (3)
Curator verdict
Pick a side. Mixing Cal.com's light-first canvas with PostHog's expressive motion vocabulary produces visual whiplash. Adopt one system as your primary, study the other for individual technique transfers (e.g. Cal.com's spacing, PostHog's shadow).