Website background opacity.

10 to 25% gives texture that doesn't fight the text; 30 to 50% adds interest while staying readable with good contrast. Test with the real typography.

Process the image at 15 to 30% and lay it over the background color in CSS. The depth stays, the focus stays on the headline and the buttons.

Yes. A linear fade to 0% at the top and bottom removes the hard boundaries between sections as the page scrolls.

Make two files. Dark backgrounds usually want lower opacity, 10 to 20%, than light ones, 20 to 40%, for the same effect.

Yes. A repeating pattern at 5 to 15% opacity, tiled with background-repeat, adds dimension without noise.

No. The browser decodes the file, a canvas does the work and the result is built on your device; the page makes no request with your image. You can load it, go offline and keep working.

The edit is written as a PNG so nothing is lost: it keeps every pixel and the alpha channel exactly. Run the result through the WebP compressor to get a WebP back for the web, usually 25 to 35% smaller than the PNG.

A baked opacity means the browser renders one image rather than compositing layers at runtime, which can help paint performance on complex backgrounds.

No. The "Website background opacity" tool is free and opens without a sign-in, an account or an install.

Nothing. The "Website background opacity" tool holds your input in the page's memory, so closing or reloading the tab clears it, and it saves nothing in this browser.

Up to 100 MB per file, the limit the tool states under its drop area. A larger file is refused with a plain message instead of being decoded.

No, it takes one file at a time. If you drop or choose several, only the first is used; run the tool again for the next one.

The edit is written as a PNG because PNG stores every pixel exactly, with a full alpha channel, so the result can be edited again without a second round of loss.

No. The browser decodes the image and the tool writes a new file from its pixels, so camera EXIF, GPS position and text chunks in the original are not copied into the result. Keep the original file if you need them.

No. The result has the same width and height in pixels as the source.

Closest to the "Website background opacity" tool: WebP opacity changer, Hero section image fade, Website image color styling, PNG opacity changer. Each opens on its own page, free and in the browser.

The "Website background opacity" tool is one of 44 in its group. The group's page, /tools/webp, lists them all.

The tool is free. Its interface is built from shadcn.io's own components (Button, Input, Slider and the rest of the registry under /ui), which come in React, Vue, Svelte and Solid. Pro adds the blocks and templates for the product around it.