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Make your logo brighter than white

▲ 71 points 86 comments by telecuda 1d ago HN discussion ↗

Pangram verdict · v3.3

We believe that this entire text is AI.

99 %

AI likelihood · overall

AI
0% human-written 100% AI-generated
SEGMENTS · HUMAN 0 of 1
SEGMENTS · AI 1 of 1
WORD COUNT 523
PEAK AI % 99% · §1
Analyzed
Aug 22
backend: pangram/v3.3
Segments scanned
1 windows
avg 523 words each
Distribution
0 / 100%
human / AI fraction
Verdict
AI
Pangram v3.3

Article text · 523 words · 1 segments analyzed

Human AI-generated
§1 AI · 99%

Upload a logo, choose which colors should glow, download an HDR JPEG. On HDR screens the chosen parts shine up to 7.5× brighter than #FFFFFF. Everywhere else it's a perfectly normal JPEG.Drop your logo here, or click to choosePNG, JPEG or WebP · free · nothing is storedISO 21496-1 gain-map JPEGBT.2100 PQ for LinkedInbase pixels untouchednothing storedfreeTwo identical #FFFFFF squares.One carries a gain map.SDR whiteas bright as a screen normally goesHDR white · +2.9 stopsup to 7.5× brighterChecking your display and browser…ExamplesOriginal artwork, converted with this tool. Drag the handle; on an HDR display in a capable browser the right side glows. “Use this” loads the original into the tool above.The wordmarkWhite type on black — the classic case. The whites are selected automatically.glows: whitesOrbit markA white ring plus one brand color. Whites and the blue are both pushed to the same peak.glows: whites + #2f6bffSticker badgeCream type on dark teal — not white, so it's picked as a color. Light elements on dark backgrounds glow best.glows: #f5e9c8How it worksYour JPEG stays a normal JPEG. For the web we add an ISO 21496-1 gain map — a second, tiny grayscale image that tells HDR-aware software how much brighter each pixel may go. For LinkedIn we write the pixels in BT.2100 PQ with the matching ICC profile, which LinkedIn preserves.What glows bestLight, near-white elements on dark backgrounds. Strong (+2.9 stops, ~1,500 nits) is the measured real-world sweet spot. Dark colors can't really glow — boosting them reads as washed neon.Honest limitsHDR only shows on HDR displays in software that honors gain maps or PQ profiles (Chrome, Safari 26, Apple Photos, LinkedIn's apps). Most other platforms strip or normalize it — the file still looks perfectly normal there.Also works on textText can be brighter than white, too.CSS has no way to write a color brighter than #FFFFFF yet — the HDR color spaces in CSS Color HDR are still a draft. But you can paint real text through an HDR image: background-clip: text turns the glyphs into a window onto a gain-map JPEG. The headline at the top of this page is exactly that — select it, it's text.Brighter than whiteSDR textcolor: #fffBrighter than whiteHDR textbackground-clip: text over the swatchChecking your display and browser…Where it works: wherever gain-map JPEGs render — Chrome 137+, Safari 26 / iOS 26 — on an HDR display. Elsewhere the swatch's base image shows through, so the text is simply white. Nothing breaks.The swatch is a 64×64 white JPEG carrying a uniform gain map (7.5×, +2.9 stops, ~1,500 nits); the browser scales it under the glyphs. Any boost works: upload a white square to the tool above and pick an intensity.Mind the box: background-clip only paints ink inside the element's box, so a line that overflows gets clipped. Give tight headlines room (ours borrows a bit of its grid gap).Headlines and accents only. A paragraph at 1,500 nits is hostile. Add fallbacks for ::selection and @media print.Why not filter: brightness()? The page is composited in SDR; no filter or blend mode pushes a CSS color past white. Only HDR content gets the headroom — which is what the swatch is.