On-the-fly image API

Build the image in the URL.

Point Refract at your image origin and shape every render from the query string — nothing re-uploaded, everything fetched on demand and cached at the edge.

https://demo.refract.dev/hero.jpg?fm=auto&q=80 Negotiated

A sunlit whitewashed terrace with a deep arched opening framing a calm blue sea — Live preview — original source

Capabilities

Transform, optimize, deliver.

A bright interior room with a tall window and a single wooden chair

Transform

Ten chainable URL parameters reshape any source in the request. Smart crop keeps the subject in frame.

w=1200 · fit=crop · crop=smart

A coastal horizon at golden hour with smooth tonal gradients across sky and water

Optimize

fm=auto negotiates AVIF, WebP, or JPEG from the request's Accept header — an average 62% smaller than the source JPEG.

fm=auto · q=80

An aerial view of a coastal road curving between cliffs and open sea

Deliver

41 edge locations answer a cached request in a median 21 ms, at a 98.6% cache hit ratio.

w=1200 · dpr=2 · fm=auto

Live transform

See it happen.

The right plate is the source on the left, redrawn by the parameters set in the bar above — in your browser, nothing pre-baked.

Source

A shallow ceramic bowl of whole citrus on a pale wooden table beside a window

Transformed

The same bowl of citrus, redrawn by the current transform parameters

No parameters set — the result matches the source.

62% average payload reduction

21 ms median cached response

98.6% cache hit ratio

99.95% uptime SLA (Scale)

Start with a single request.

Start building