Can a web page make one thing brighter than white?

On a compatible HDR display, the right mark requests luminance above CSS reference white.

Experiment

HDR display query Checking…
Extended WebGPU canvas Checking…
SDR reference CSS white · 0 stops
HDR target WebGPU · +2 stops requested

Each stop doubles linear light. OS and display cap the result.

Initializing…

LinkedIn export

Turn a logo into a Rec.2020 PQ JPEG for LinkedIn. White areas can render above reference white on Apple EDR screens. Nothing leaves your browser.

Upload a logo or mark. Processing stays in your browser.
Upload notes
  • Upload from desktop Chrome or Safari, not the iOS photo picker.
  • Do not crop or filter inside LinkedIn after upload.
  • Works best on company pages; personal profiles may recompress.
  • Preview here is SDR. Check the glow on an iPhone or XDR Mac.

How

CSS white is SDR reference. A 16-bit float WebGPU canvas with toneMapping: { mode: "extended" } can emit values above 1.0.

Browsers report HDR availability, not nits. Outcome depends on display, headroom, and settings.

Sources