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Design language comparison

Comet vs PostHog

Comet runs a dark-canvas system while PostHog chose light, and they pair different display families (system-ui vs Open Runde). Beyond surface, motion levels are both expressive.

Palette · side by side

Up to 8 dominant swatches each

Side A · dark

Comet

Full Page

#313131

foreground

#0000ee

brand

#d9d9d9

neutral

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 + sample

Side A · dark

Comet

Full Page

Display
system-ui
Body
monospace
Mono
monospace
Weights
400 · 600

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 values

Side A · dark

Comet

Full Page

Base unit
8 px
Container max
960 px
8px
16px
32px
128px

Side B · light

PostHog

Full Page

Base unit
4 px
Container max
320 px
2px
4px
6px
8px
10px
12px
14px
17px

Motion vocabulary · side by side

Level + durations + easings

Side A · dark

Comet

Full Page

Level
expressive
Libraries

Durations

400ms600ms900ms1200ms

Easings

cubic-bezier(0.16, 1, 0.3…cubic-bezier(0.22, 1, 0.3…

Side B · light

PostHog

Full Page

Level
expressive
Libraries

Durations

0.15s0.3s3s4s4.9s

Easings

cubic-bezier(0.4, 0, 0.2, 1)cubic-bezier(0.16, 1, 0.3…ease-in-outlinear

Palette & spacing overlap

Palette overlap is zero — Comet and PostHog live in completely different chromatic registers, even when their layout grids feel adjacent. Their spacing scales overlap by 17% (8, 32 px shared) — a rhythm any agent can transfer between the two systems with minimal recalibration.

Curator verdict

Pick a side. Mixing Comet's dark-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. Comet's spacing, PostHog's shadow).

Full Comet brief →Full PostHog brief →Back to gallery

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