HDR glow tools compared: which one actually works on LinkedIn

superwhite.app · comparison · updated 7 September 2026 · by Nimrod Yarkoni

I build one of the tools on this page, so read it with that in mind. I have tried to write the comparison I wanted when I started, which means saying plainly where the free options are the right answer.

In the space of about eight months the glowing LinkedIn logo went from one clever file to a small category. There are now at least six ways to make one. They do not all produce the same file, they do not all target the same LinkedIn surface, and most of them cost nothing.

First, the thing that actually decides your choice

Not price. Which LinkedIn surface you are posting to. There are three, and they behave differently.

• Company page logo. Widely reported to keep the effect. LinkedIn recommends 400x400, so resolution limits are irrelevant here.
• Feed post image. Also keeps the effect, as long as you upload the exported file directly and do not crop or adjust it in LinkedIn's composer. This is where size matters, because a 400px image in a feed post looks like a 400px image.
• Personal profile picture. Contested. More on this below.

The tools

There is also Gal Tidhar's CLI and Claude skill, a browser converter by Nitzan Yogev, and dtinth's open source superwhite, which is the original bright-white demo and is a different thing again: a tiny HDR video used to paint brighter-than-white on a web page, not an image converter. The underlying idea of pushing HDR profiles into marketing images was documented by Tom Nick before any of this.

HDRLogoGlow, the newest entry, is the one that goes furthest beyond the white case: it can glow any colour or a single selected region, shows the exact-colour brightness ceiling for the colour you picked, and ships an HDR display test and a colour limit calculator as side tools. It is free. Its public material does not describe near-white flattening, PQ dithering or chroma handling, and its LinkedIn page lists the paid ad path as untested. There is a direct head to head in HDRLogoGlow vs Superwhite.

What the technical differences actually change

PQ profile versus gain map

Most of these tools take the same route, because it is the route that works: encode the pixels with the PQ transfer function and put a Rec.2020 or Rec.2100 PQ ICC profile in the file. LinkedIn re-encodes every upload and discards gain map metadata, but preserves colour profiles, so the brightness has to travel inside colour management.

So Very Bright is the outlier, writing a gain map under ISO 21496-1. Gain maps are the more standards-correct way to do HDR images and they render beautifully in Apple Photos and modern browsers. Whether a given gain map file survives a given platform's re-encode is a separate question from whether it looks right on your desktop, and that is worth testing on your own account before you commit a brand asset to it.

The threshold, and what happens to everything that is not white

Tagging an image as PQ without touching the pixels boosts the whole frame, including the parts you did not want lit. The tools that handle this well apply a ramp: pixels above some share of white get boosted, everything below keeps normal brightness, and antialiased edges blend instead of haloing. superGLOW and the Adamodigi skill both do this. Superwhite exposes the threshold as a control, because the right value for a wordmark on navy is not the right value for a photo.

The part nobody mentions: compression noise

A JPEG that looks clean at normal brightness is not clean. There is invisible encoding noise sitting in the near-white range, a few code values wide. Boost those pixels to 1,000 nits and the noise comes with them, which reads as blotching across what should be a flat white field. Superwhite flattens the near-white band before the boost for exactly this reason, and encodes at 4:4:4 rather than the 4:2:0 a browser canvas gives you by default, because 4:2:0 smears the edges of coloured marks. If you are converting a clean vector logo with hard whites, none of this will ever bite you. If you are converting a compressed photo or an export that has already been through a few tools, it will.

The profile picture disagreement

This is the one open contradiction in the category, and it is worth knowing about before you spend an afternoon on it.

Some tools advertise profile picture support and publish converted headshots as evidence, describing shirts and backgrounds glowing while skin tones stay natural. Others state the opposite: that LinkedIn's avatar pipeline converts the upload to a plain PNG with colour chunks stripped, which would remove the effect entirely, and that only company page logos pass through untouched.

Both positions come from people who inspected real files. The most likely explanation is that the avatar pipeline is not the same everywhere or has changed at some point, which is normal for an undocumented pipeline that nobody at LinkedIn has committed to keeping stable. Until that is settled, the honest advice is: company logo and feed post are reliable, profile picture is a coin toss, and you should verify on your own account from an HDR device before you tell anyone it worked.

So which one

• Just a company logo, once. If cost is the deciding factor, use one of the free tools here. Superwhite is 3 euro one time for unlimited 400px exports, which buys you the threshold control and noise handling rather than a bigger file.
• You want the file without a browser, inside an automated workflow. The Adamodigi skill or Gal Tidhar's CLI. Both are open source and drop into a script.
• Full size feed post images and ads. This is the one place the free tools thin out, since most of them are built around the 400px logo case. Superwhite's Creator tier at €5 once goes to 1400px and Pro at €9 a month goes to 3840px.
• Many brands, repeatedly. Batch export and saved per-brand settings are a Superwhite Pro thing rather than a category thing, because agencies were the ones asking for it.
• You care about standards correctness more than LinkedIn survival. Look at the gain map route.

One thing worth saying about all of them

This is attention arbitrage and it is on borrowed time. Platforms clamped auto-HDR video brightness after the same trick flooded short-form feeds, and there is no reason images are permanently exempt. There is already a visible backlash arguing that glowing logos degrade a shared feed for local gain, and that argument is not wrong.

Which is an argument for taste rather than for abstinence. A wordmark that reads as lit is craft. A full-frame 4,000 nit flashbang in someone's dark bedroom is a pop-up ad, and it is the behaviour that will get the door closed for everyone. Turn it down.

Frequently asked questions

What is the best free tool to make a logo glow on LinkedIn?

For a company logo at no cost: HDRLogoGlow, superGLOW, Hirenum Logo Glow and So Very Bright. Superwhite is paid, 3 euro one time for unlimited exports up to 400px, so the reason to pick it is output quality rather than price. LinkedIn recommends 400x400 for company logos, so any of these covers that size.

Do these tools all produce the same file?

No. Most encode the pixels with the PQ transfer function and embed a Rec.2020 or Rec.2100 PQ ICC profile, because that is what LinkedIn preserves. So Very Bright writes a gain map under ISO 21496-1 instead. Among the PQ tools, the differences are in the glow threshold, near-white noise handling, chroma subsampling and dithering.

Does the glow work on a LinkedIn profile picture?

Reports conflict. Some tools publish converted headshots as evidence it works. Others report that LinkedIn's avatar pipeline strips colour information on upload. Company logos and feed posts are the two surfaces widely reported to survive, so use those and verify anything else yourself on an HDR screen.

Why is Superwhite paid when other tools are free?

Because the pixel handling is the work: amplified near-white noise, chroma smearing on coloured edges, and 8-bit banding all have to be solved or the glow looks dirty. It is maintained as a product rather than published as a one-off script, and that is what the paid tiers fund. Exports are 3 euro one time.

Who invented the LinkedIn HDR glow trick?

Tom Nick documented the underlying technique. Gal Tidhar reverse engineered the company logo variant after the Wiz logo went around and credited the earlier lineage, including Port shipping it before Wiz and dtinth's open source demo. Everything current builds on that public research.