Real screen-blend glow
The tool isolates the bright areas, blurs them, then screen-blends the glow back over the image — the same technique games and film use for halation and dreamy highlights.
ImageRuns in your browser
Bloom Image Effect
Add a dreamy soft glow that makes highlights bleed light.
- Upload
- Single file · 25 MB max
- Privacy
- Nothing is uploaded
- Cost
- Free · no sign-up · no watermark
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Processed entirely on your device
Your file is read, transformed and re-encoded inside this browser tab using JavaScript. There is no upload endpoint — nothing leaves your machine, nothing is stored, and the result is created as a local object URL that disappears when you close the page.
Overview
About the Bloom Image Effect
Add a bloom effect free online that makes bright highlights glow and bleed for a dreamy, ethereal look. Adjustable radius, in your browser with CollabsTool.
What bloom does
Bloom, also called halation or glow, happens when bright light bleeds past its edges into surrounding darker areas. This tool recreates it digitally: it extracts the highlights, blurs them into a soft glow, then screen-blends that glow back over the original so the image stays sharp while lights shimmer.
The dreamy look
A gentle bloom softens harsh highlights and adds a romantic halo, which is why it is a staple of portrait, wedding, fantasy and game art. Pushed further it creates an ethereal, almost otherworldly atmosphere.
Controlling the glow
The radius slider decides how wide the bleed is. Small values add a subtle sheen to the brightest points; large values spread a broad, hazy glow. Because only highlights are affected, mid-tones and shadows keep their detail.
On-device and lossless
The bright-pass, separable blur and screen blend are all computed on an in-browser canvas and exported as a PNG, keeping your photo private and full resolution.
Step by step
How to use the Bloom Image Effect
Drop a photo with bright highlights onto the upload area.
Raise the glow-radius slider; highlights start to bloom outward.
Backlit subjects, lights and skies glow most beautifully.
Download the bloomed PNG at full original resolution.
Why use it
Benefits and common use cases
What this tool is good for, and what it deliberately does not try to do.
Dreamy, ethereal mood
Bloom softens harsh light and adds a romantic halo around highlights, ideal for portraits, fantasy art, sunsets and atmospheric scenes.
Local and lossless
The bright-pass, blur and blend all run on an in-browser canvas and export PNG, so your photo is never uploaded and keeps full resolution.
Questions
Frequently asked questions
Short, honest answers about quality, limits and privacy.
What does the glow radius control?
It sets how far the light bleeds from bright areas. A small radius gives a tight, subtle sheen; a large radius spreads a wide, dreamy halo around highlights.
How is bloom different from blur?
A blur softens the entire image. Bloom only blurs the bright highlights and blends that glow back, so the image stays sharp while lights appear to bleed and shimmer.
Which images bloom best?
Those with strong highlights against darker areas — backlit portraits, city lights at night, candles, sunsets and window light. Flat, evenly lit photos show little effect.