Where it survives
LinkedIn company logos and feed images, uploaded as the exported JPEG. Don't crop or adjust it in LinkedIn's composer — that re-encodes through a different path.
ST 2084 PQ · BT.2020 · ICC v4.4 with CICP
Whites brighter than white.
Your screen has brightness it doesn't use for ordinary white. This writes your logo's whites into that headroom as absolute luminance, wrapped in the one HDR format that survives LinkedIn's re-encode.
Runs entirely in your browser · nothing is uploaded
THIS BAND IS PURE WHITE ON PURPOSE
MEASURED ON A LIVE LOGO
OriginalSDR · 203 nits
EncodedHDR · 3,085 nits
Same pixels, same page. If your display is HDR, the right mark is emitting more light than the white around it right now.
HOW IT WORKS
Three steps, no accounts, no upload.
The encoder rewrites your logo's white values as absolute luminance and attaches an ICC v4.4 profile carrying CICP tags, so platforms that re-encode the file keep the HDR signal intact. Read the full method →
01
Drop in flat artwork
Wordmarks, monograms and flat illustration with genuinely white areas. Transparency is composited onto the background colour you choose, because JPEG has no alpha channel.
02
Set the exposure
Choose how far above diffuse white the highlights sit, and whether the lift applies to whites only, bright areas, or every pixel. Presets cover the safe range.
03
Download and upload untouched
The encoded tile you see is the real output file, not a simulation. Move the JPEG itself — any re-save or crop strips the profile.
THE BENCH
Encode a logo.
1 · Source
Drop a logo here
PNG, JPEG, WebP or SVG · or click to browse · or paste from the clipboard
Flat artwork with genuinely white areas works best. Transparency is composited onto the background colour you choose, because JPEG has no alpha channel.
3 · Compare
awaiting source
awaiting encode
Against page white
The encoded tile is the real output file, not a simulation.
2 · Exposure
Preset
What glows
Background
#000000
On white, the whole tile glows. Dark backgrounds keep it a spotlight.
| Transfer function | SMPTE ST 2084 (PQ) |
| Primaries | ITU-R BT.2020 |
| Profile | Rec2020 Gamut with PQ Transfer |
| HDR signalling | ICC v4.4 cicp 9 / 16 / 0 / 1 |
| Diffuse white | 203 nits (BT.2408) |
| Peak white | 3,030 nits |
| Above 1,000 nits | — |
| Chroma | 4:4:4, no subsampling |
BEFORE YOU UPLOAD
Where the glow lives, and where it dies.
Where it dies
Screenshots, re-saving in any editor, conversion to another format, and messaging apps that recompress. Profile pictures too — confirmed by inspection, LinkedIn's avatar pipeline converts the upload to a plain PNG with every colour chunk stripped, not just the HDR one. Move the file itself, untouched, as a feed post or company logo instead.
Who sees it
People on HDR displays with HDR active and battery saver off. Everyone else sees an ordinary logo, which is what makes this safe to ship.
What to feed it
High-contrast marks: wordmarks, monograms, flat illustration. Photographic gradients band at 8 bits — dithering helps, but it can't add depth that isn't there.
QUESTIONS
Ten answers before you ask.
Still unsure whether your artwork qualifies? Drop it on the bench — the comparison runs locally and costs you nothing.
Why do some LinkedIn logos look brighter than my screen?
They are HDR images. The file states its brightness in absolute units — nits — rather than relative to screen white, and an HDR display honours that. The rest of the page stays at normal brightness, so the logo appears to glow.
Why did my Photoshop HDR export lose its glow after uploading?
Camera Raw exports a gain-map HDR JPEG: a normal image plus a hidden second image describing the boost, referenced by XMP metadata. LinkedIn re-encodes every upload and discards both. It preserves ICC colour profiles, so the brightness has to travel inside the profile instead.
What exactly does this tool write into the file?
Pixels converted to BT.2020 primaries and encoded with the ST 2084 PQ curve at absolute luminance, wrapped in an ICC v4.4 profile carrying a CICP tag of 9/16/0/1. No gain map, no XMP, no EXIF — nothing a re-encoder can strip and break.
Does my image get uploaded anywhere?
No. The encoding runs in your browser using canvas and a few hundred lines of JavaScript. The server sends you the page and never sees your artwork. You can disconnect from the network after the page loads and it still works.
Who will actually see the glow?
Anyone on an HDR-capable display with HDR enabled: recent iPhones and iPads, modern MacBooks, and flagship Android phones. Everyone else sees a normal logo. That graceful fallback is what makes the technique safe to ship.
How bright should I go?
A logo pulled from a live LinkedIn page measured 3,085 nits, about +3.9 stops over diffuse white — but its mark covered only 8% of the tile on a pure black background. Brightness budget scales inversely with how much of the tile lights up. The coverage readout warns you when too much of yours is above 1,000 nits.
What kills the effect?
Screenshots, re-saving in another editor, converting to PNG, and messaging apps that recompress. Anything that rewrites or drops the ICC profile. Move the exported file itself, and do not crop it in LinkedIn’s composer.
Does this work on Instagram or X?
Not reliably. The technique depends on a pipeline that preserves ICC profiles through re-encoding, which LinkedIn does today. Most other platforms strip them or expect a different HDR format entirely. Test before you rely on it, and expect it to change.
Can I use this as my LinkedIn profile picture?
No. Confirmed by fetching the actual file LinkedIn serves back: the avatar pipeline converts the upload to a plain PNG with every colour chunk stripped — no ICC, no cICP, not even a basic sRGB tag — which is a different, more destructive path than feed posts or company logos. Post it as a feed image or set it as your company page logo instead.
What is the PNG control file for?
It carries the same pixels signalled through a PNG cICP chunk, which browsers handle more consistently than ICC-in-JPEG. It is a diagnostic: if the PNG glows and the JPEG does not, your encode is correct and your viewer is the limitation.
Give your mark the headroom.
One file, encoded in the browser, ready to upload. Nothing to install and no account to make.
Encode a logo