Demo Pretext: Instant Layout Engine — Zero-reflow text measurement for real-world UI

Responsive Height Predictor

Type or paste text, adjust the container width, and watch Pretext calculate height and line count instantly via canvas-cached arithmetic.

400px
16px

Pretext (arithmetic)

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Height (px)
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Lines
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Time (μs)

DOM measurement (reflow)

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Height (px)
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Lines
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Time (μs)
Pretext speedup --×

Pre-measured Masonry Cards

Every card height is predicted by Pretext before rendering. The masonry layout is computed from those heights with zero DOM reads. Resize or change columns and watch it recalculate.

14px
Pretext: -- μs for 0 cards