Transparency check notes
The checker reads rendered pixels from a local canvas and counts transparent and semi-transparent alpha values.
It helps you decide whether to preserve transparency, add a background or convert the file to JPG.
PNG Transparency Checker
Inspect PNG or WebP transparency before converting, adding a background or trimming empty transparent edges.
Alpha channel scanTransparent pixel countEdge transparency checkNo upload
PNG transparency checker
Result preview
Choose an image or enter dimensions to see results.
Choose an image or enter dimensions to see results.
How it works
- 1Choose a PNG or WebP image.
- 2ImgShrink scans the alpha channel in the browser.
- 3Review whether the file has transparent pixels, semi-transparent pixels or transparent edges.
Privacy and limits
- This checker reads rendered pixels, not every possible editor-layer property.
- JPG files do not support transparency.
- The file is not uploaded or saved.
Common use cases
- Check if a PNG really has a transparent background
- Find whether only the edges are transparent
- Decide whether a transparent image is ready for JPG conversion
Alpha channel notes
- Fully transparent pixels have alpha 0.
- Semi-transparent pixels have alpha values between 1 and 254.
- JPG does not support transparency.
Original test sample
- Upload a transparent PNG logo and confirm transparent pixels are detected.
- Upload an opaque PNG screenshot and confirm it is reported as not transparent.
Frequently asked questions
Are my images uploaded?
No. ImgShrink processes selected images in your browser and does not upload them to a server.
Can this tool guarantee an exact file size?
No. Target compression gets close when possible, but the final bytes depend on image detail, dimensions, format and browser encoding.
Why is an output format unavailable or different?
The browser controls image decoding and export support. Some browsers may not export AVIF or may flatten unsupported transparency.
Source and compatibility notes
This tool works in the browser, so output support depends on what your browser can read and export.
Last checked: 2026-09-07
Notes
- No server-side image processing is used.
- Output format support depends on the browser.
- Animated images and metadata are not treated as guaranteed preserved data.
Related transparency tools
All toolsAutomatically trim transparent edges from PNG or WebP images in your browser. See cropped margins, new dimensions and download the result.
Add a white, black or custom color background to a transparent PNG or WebP in your browser. Preview and download JPG, PNG or WebP.
Convert PNG images to JPG in your browser. Flatten transparency to white and download a compatible JPG file.
View image metadata, EXIF, GPS status, file size and pixel dimensions in your browser. No upload required.