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…

HDR export

Turn a logo into Rec.2020 PQ files for LinkedIn or X. 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 the raw file. Do not crop or filter inside LinkedIn or X after upload.
  • X export uses Floyd-Steinberg dither + indexed PNG + Rec.2020 PQ ICC.
  • Works on EDR displays (iPhone, XDR Mac). Preview here is SDR.
  • LinkedIn works best on company pages; personal profiles may recompress.

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