Image Tools / Local studio

Image Opacity Adjuster

Scale every decoded alpha value to a selected percentage, retain RGB values and dimensions, and export a transparency-safe PNG.

Runs locallyNo image upload to Nirmion

Step 1 / Source

Choose one image

JPEG · PNG · WebP · 20 MB

Drop your image here

Or browse for a JPEG, PNG, or WebP image that you own or are authorised to edit.

Browse imageOne file · up to 20 MB · maximum 50 megapixels

Step 2 / Output

Image Opacity Adjuster controls

Choose 0% for fully transparent through 100% for the original alpha; export is forced to PNG to retain transparency. Processing stays in this browser tab.

Output opacity 70%Choose 0% for fully transparent through 100% for the original alpha; export is forced to PNG to retain transparency.

Create the opacity-adjusted PNGThe source is not overwritten. Export creates a separate opacity-adjusted PNG.

Keep this page open until the download begins.

01No server upload

The selected image is decoded and re-encoded inside this browser tab.

02Working copy released

After download, the preview URL, decoded bitmap, canvas, and selected source reference are cleared.

03Your download remains

Nirmion cannot remove the finished file from your device or browser download history.

Workflow guide

Use image opacity adjuster with a reversible review path

Every existing alpha byte is multiplied by the selected percentage while decoded red, green, and blue values remain unchanged. Compare the derivative with the untouched source before using it downstream.

What you need

Choose one authorised JPEG, PNG, or WebP still image up to 20 MB and 12 million decoded pixels. Animated frames are not processed.

Social-ready choices

Prepare a semi-transparent overlay asset, then test it against the actual light and dark backgrounds where it will be composited.

What you receive

Download a separate opacity-adjusted PNG; the original file on your device remains unchanged.

Decision guide

What image opacity adjuster changes

Every existing alpha byte is multiplied by the selected percentage while decoded red, green, and blue values remain unchanged.

Uniform opacity does not remove a background, create a mask, isolate subjects, or predict appearance over an unknown backdrop. Browser-local processing avoids a Nirmion file upload, but it cannot remove copies stored elsewhere.

W3C Compositing and Blending Level 1

Useful checks for image opacity adjuster

Prepare a semi-transparent overlay asset, then test it against the actual light and dark backgrounds where it will be composited.
Create a review derivative while retaining the original for correction, comparison, or a different export.
Test the operation on representative shadows, midtones, highlights, edges, text, and transparent areas.

Good to know

Important image boundaries

Why might a PNG not become smaller?: PNG is lossless and browsers do not expose a quality control for it. Choose WebP or JPEG when reducing file size matters more than exact lossless pixels.
Are animated images supported?: No. The workspace accepts still JPEG, PNG, and WebP files. Re-encoding an animated source would otherwise keep only one frame.
What does clearing the file mean?: Because processing is local, there is no Nirmion server copy to delete. The tab releases its working references after success; your downloaded output remains on your device.

Questions answered

Frequently asked questions

Does Image Opacity Adjuster upload my image?

No. For supported JPEG, PNG, and WebP inputs, decoding, pixel transformation, canvas rendering, and export run in your current browser tab. Nirmion does not send the selected image to its API for this workflow. The output is a new derivative, while the original file on your device remains unchanged and should be retained for comparison or later editing.

How does Image Opacity Adjuster change pixels?

Every existing alpha byte is multiplied by the selected percentage while decoded red, green, and blue values remain unchanged. Existing alpha is scaled uniformly and output is forced to PNG; RGB bytes are retained. The operation does not infer subjects, recover clipped detail, calibrate a display, or develop raw camera data. Inspect fine edges, gradients, text, skin tones, and transparent pixels in the exported file before relying on the result.

What are the practical limits of Image Opacity Adjuster?

Uniform opacity does not remove a background, create a mask, isolate subjects, or predict appearance over an unknown backdrop. The workspace accepts one supported still image up to 20 MB and caps this pixel-intensive operation at 12 million decoded pixels for predictable browser memory use. Output depends on browser decoding and encoding support. Animation, raw development, ICC calibration, layer editing, and batch processing are outside this tool's verified scope.