Turn a single flat or high-contrast photo into a vivid HDR-style image. The tool opens up dark shadows, holds back bright skies and sharpens local detail with edge-aware tone mapping. Drag the strength slider, compare before and after, and download the full-size result.
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BeforeAfter
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How to use the HDR Photo Effect
Add a photo by dropping it in the box, pasting it or pressing Choose photo. A sample landscape is loaded so you can try the sliders first.
Pick a preset such as Natural or Dramatic as a starting point.
Adjust HDR strength to compress the bright and dark areas, then use Detail for texture and Glow radius for how local the effect is.
Drag the before / after divider across the image to check skies, faces and edges for halos.
Download the full-size result as JPG, PNG or WebP.
How the single-image HDR effect works
The tool performs local tone mapping on the logarithm of each pixel's luminance (Y = 0.2126 R + 0.7152 G + 0.0722 B). Working in log space means a change of 1.0 is a fixed number of stops anywhere in the image, the same way the eye judges brightness.
Split into layers. A self-guided filter (an edge-preserving smoother) produces a large-scale base layer and a small-scale one. The image becomes base + mid-scale contrast + fine detail.
Compress the base. The base is scaled toward its median by a factor of 1 − 0.68 × strength, which shrinks the brightness gap between sky and ground.
Boost the detail. Mid-scale contrast is multiplied by up to 2.3× and fine texture by up to 3.6×, so local contrast is stronger than the original even though global contrast is lower.
Restore color. The new luminance is applied to the original color ratios, then saturation is adjusted and any channel above white is compressed toward gray instead of clipping, which keeps hues stable.
Recommended settings by subject
Subject
Strength
Detail
Glow radius
Saturation
Landscape with bright sky
55–70%
35–50%
4–6
110–120%
Interior with windows
70–85%
25–40%
5–7
100–110%
Old buildings, cars, machinery
75–90%
70–100%
2–3
90–125%
Portraits
20–40%
0–20%
6–10
100–105%
Night city scenes
50–65%
30–45%
3–4
110–120%
Tips for a convincing HDR look
Start with Natural. A subtle effect looks like a better camera; a strong one looks like a filter. Push further only on subjects that suit it.
Check edges with the divider. Bright outlines along a skyline mean the glow radius is too wide for that strength.
Noisy photo? Detail enhancement also boosts noise. Clean the photo first with the Image Noise Remover, or keep Detail below 30%.
Clipped sky? If the sky is pure white in the original, no tone mapping can recover it. Shoot bracketed exposures and combine them with HDR Merge.
Frequently asked questions
Can you make an HDR photo from a single image?
You can create the HDR look from one image. True HDR merging combines several exposures to capture more light information, but a single photo already holds more tonal detail than it shows. Local tone mapping brings that hidden detail out by brightening shadows and darkening highlights region by region. For scenes where the sky is pure white or the shadows are pure black in the original, use HDR Merge with bracketed shots instead.
What does the HDR strength slider do?
It controls how much the large-scale brightness differences are compressed. At 0% the photo keeps its original contrast between sky and ground; at 100% the range between the brightest and darkest regions shrinks to about one third, so shadows open up and bright areas are pulled down. The report under the image shows the scene range in EV (stops) before and after.
How is this different from just raising contrast or brightness?
Global adjustments apply the same curve to every pixel, so brightening the shadows also blows out the sky. This tool splits the image into a smooth base layer and a detail layer with an edge-aware filter, compresses only the base layer and then adds the detail back, boosted. That is why dark foregrounds get lighter while clouds keep their texture.
Why do I see halos around trees or buildings?
Halos appear when the base layer blurs across a strong edge. The tool uses a guided filter that stops at edges, which keeps halos small, but very high strength with a wide glow radius can still create them. Lower the glow radius, reduce strength or use the Natural preset for a cleaner look.
Which photos work best with an HDR effect?
Landscapes with a bright sky and a darker foreground, architecture and interiors with windows, cars, old buildings and textured subjects such as rock, wood and rust. Portraits usually look better with low strength and low detail, because heavy detail enhancement exaggerates skin texture.
Will the download be full resolution?
Yes, up to 4000 pixels on the long side. Larger photos are scaled down to 4000 px for processing so the effect works reliably in browser memory. The preview uses a smaller copy for speed, and the radius settings scale with the image so the download matches what you see.
Is my photo uploaded to a server?
No. All processing runs in JavaScript in your browser, so the photo stays on your device and the tool keeps working without an internet connection once the page has loaded.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.