How to convert HDR photos to standard SDR (and why they glow on screens)
Written for photographers, web designers and everyday phone users whose HDR photos look overly bright, clipped or colour-shifted when uploaded to websites or chat apps
Short answer
Modern iPhones and Android 14+ phones shoot High Dynamic Range (HDR) photos that pack extra brightness instructions, called a gain map, alongside the normal 8-bit image. On HDR-capable OLED phones and MacBook Pro screens, that gain map makes highlights glow brighter than normal browser white; on older upload forms or apps that misread the colour profile, the photo can look washed out or neon. Re-saving or stripping the gain-map metadata in our browser tools flattens the file into a clean, predictable Standard Dynamic Range (SDR) JPEG, PNG or WebP that looks identical on every screen.
On this page
Have you ever scrolled through a webpage or chat thread, landed on a single smartphone photo, and watched that one picture glow like a neon lightbox while the white webpage around it suddenly looked muddy grey? Or uploaded a portrait to a website only to see the skin tones turn radioactive orange or flat and washed out?
That is the side effect of gain-map HDR photos (Apple’s Smart HDR / ISO 21496-1 and Google’s Android Ultra HDR format). Here is how they work inside the file and two ways to convert them to clean, predictable SDR (Standard Dynamic Range) in your browser.
What is inside an Ultra HDR or iPhone HDR photo
Traditional JPEG, PNG and WebP files are SDR: pure black is 0 and the brightest possible white on the webpage is 255.
Modern phone cameras capture more dynamic range than 0–255 can hold. Rather than inventing a brand-new file extension that nothing can open, Android’s Ultra HDR specification and Apple’s HEIC/JPEG exports pack two things inside one JPEG container:
When you should keep HDR vs convert to SDR
| Use case | Keep HDR or convert to SDR? | Why |
|---|---|---|
| Website product photos, blog graphics & avatars | Convert to SDR | Prevents a single photo from overpowering your page’s white background and typography on MacBook Pro and iPhone OLED screens. |
| Passport, visa & government form uploads | Convert to SDR | Automated portal validators often reject files with multi-picture (MPF) secondary streams or wide-gamut profiles. |
| Editing or compositing in standard design tools | Convert to SDR | Keeps brightness predictable across layers so exported banners match what you saw on the canvas. |
| Personal photo library viewed on your own phone | Keep HDR | Preserves the sunlit sparkle on water, snow, neon signs and sunsets when viewed full-screen on an OLED display. |
How to convert an HDR photo to standard SDR in three steps
You have two local browser options depending on whether you want lossless removal of the gain map or visual tone-curve control:
- For an Ultra HDR JPEG where the base exposure already looks right, open the photo metadata remover and drop the file in; clicking Save clean copy strips the XMP hdrgm and MPF gain-map segments while keeping the 8-bit SDR base JPEG and its ICC colour profile intact with zero re-compression.
- If the photo looks too dark or too contrasty without its HDR boost, open the image brightener instead and drop the photo in.
- Adjust the Shadows and Contrast sliders until the SDR preview on screen looks balanced, then click Save photo to export a standard 8-bit sRGB JPEG, PNG or WebP with no gain map attached.
Because both tools run entirely in your browser tab, your photos are never uploaded to a remote server, and all EXIF and GPS location tags are cleaned at the same time.
Questions
Why does my phone photo make my screen dim everything else around it?
Your photo contains an HDR gain map (Apple ISO HDR or Android Ultra HDR). When an HDR-capable display renders those extra-bright highlight pixels above standard white (255), the operating system boosts backlight/OLED luminance for the photo, which makes the surrounding 8-bit webpage look dim by comparison.
How do I convert an Ultra HDR JPEG to a normal standard JPEG without re-compressing it?
An Ultra HDR file is a backward-compatible standard SDR JPEG with a secondary gain-map image stored in its metadata segments. Dropping the file into our Photo Metadata Remover splices out the secondary metadata segments and leaves the clean 8-bit SDR base JPEG untouched.
What if I want to fine-tune the brightness and shadows when converting to SDR?
Open the photo in the in-browser Image Brightener or Image Resizer. Drawing the image onto a standard 8-bit sRGB browser canvas and saving as JPEG, PNG or WebP bakes a single standard dynamic range rendition with no gain map.
How do I stop my iPhone from displaying blinding HDR highlights inside Apple Photos?
Open Settings > Apps > Photos and switch off View Full HDR. That stops your own iPhone screen from boosting HDR highlights, though the file itself still carries its HDR gain map when shared.
Why did my iPhone HEIC HDR photo look gray or desaturated on a Windows PC?
iPhone HDR photos use the Display P3 wide colour gamut plus a gain map. Older Windows viewers that ignore embedded ICC colour profiles interpret Display P3 values as sRGB, which makes reds and greens look dull.
Keep reading
How to brighten a dark photo without blowing out the highlights
Raising Brightness washes out skies and skin. Lift Shadows first, then restore a touch of Contrast and Colour in your browser.
GuideWhat is a WebP file and how do you open or convert it?
Why saved web images end in .webp, how WebP compares with JPG and PNG, and how to convert WebP without uploading your file.
GuideHow to remove photo metadata on iPhone
Turning off Location in the iPhone Share Sheet only drops GPS. Here is how to remove all EXIF, device and C2PA metadata on an iPhone.
