Image Opacity Tool
Make any photo semi-transparent with a precise opacity percentage, exported as PNG. Free, no signup, works in your browser.
Everything runs inside your browser — your file is never uploaded to a server.
About this tool
This tool adjusts an image's overall transparency using a slider from 0 to 100%, so you can turn a solid photo into a faint 15% watermark background, a soft 50% overlay for text to sit on top of, or anything in between. The change applies uniformly across the whole image, and a live preview against a checkerboard pattern shows exactly how transparent the result will look once placed over another background. Because transparency needs to be preserved in the file itself, the output is always exported as PNG regardless of whether you started with a JPG, PNG or WebP source. This is different from lowering opacity in a slideshow or website, since the transparency becomes a permanent part of the image data that any program will respect. Processing runs on an HTML canvas inside your browser, so your photo is never uploaded anywhere.
How to use this tool
1. Choose an image
Pick a JPG, PNG or WebP file from your device.
2. Set the opacity level
Drag the slider from 0 to 100% transparency.
3. Preview against checkerboard
See exactly how transparent the image will look.
4. Download the PNG
Save the semi-transparent image to your device.
Why use this tool
Reducing an image's opacity is a common step when creating watermark backgrounds, subtle overlays behind text, or soft mockup elements, but simply setting opacity in a slide or webpage doesn't change the actual file. This tool bakes the transparency into the exported PNG itself, so it stays consistent wherever the image is used afterward.
Tips & best practices
- Use 10-20% opacity for a faint background watermark that won't distract from foreground text.
- Check the checkerboard preview to judge transparency accurately before downloading.
- Pair a 40-60% opacity image with a solid colour background for a soft duotone-style overlay.
Common use cases
- Creating a faint logo watermark for the background of a document
- Making a semi-transparent hero image for text to overlay on a website
- Producing a ghosted 'before' image for a before-and-after comparison
- Softening a photo used as a subtle desktop wallpaper
- Building a translucent overlay layer for a design mockup
Frequently asked questions
Why does the output have to be PNG?
Only PNG (and WebP) can store transparency in the file itself, so true opacity changes require exporting as PNG.
Can I use this to create a watermark background image?
Yes, set opacity around 10-20% to create a faint background image or logo watermark.
Will the transparent image show correctly everywhere?
Yes, any software that reads PNG transparency, including browsers, editors and presentation software, will display it correctly.
Does lowering opacity reduce file size?
Not significantly; the pixel dimensions stay the same, only the alpha channel value changes.
Can I combine opacity with a background frame?
Yes, export the semi-transparent PNG here, then layer it over another image or design elsewhere.
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