When this tool is useful
Compatibility workflows that specifically require PNG, or images that will receive non-lossy edits after conversion.
How local processing works
The browser decodes the JPEG and stores those existing pixels in a PNG. Future PNG saves can be lossless, but prior JPEG damage remains.
How to use it
- Choose the source files.
- Review the available settings and page order.
- Process locally, inspect the result, and download it.
Important limitations
The PNG is usually larger and does not become sharper or gain real transparency simply by changing formats.
Verify the downloaded result
Reopen the downloaded file in its destination application, check dimensions or page count and visible content, and keep the source until the result has been accepted.
Private by design
Your files stay in this browser. The tool does not upload the source or output to our servers.
Questions and answers
Does this tool upload my files?
No. Processing happens in your browser; closing the page clears the working session.
Will the output always match the source exactly?
The PNG is usually larger and does not become sharper or gain real transparency simply by changing formats.
What should I check before using the result?
Reopen the downloaded file in its destination application, check dimensions or page count and visible content, and keep the source until the result has been accepted.
Which browsers and devices are supported?
Use a current browser with JavaScript, workers, canvas, WebAssembly where the format requires it, Blob downloads, and enough memory. Reopen important downloads in the destination application.
Concrete input and output example
Input a 700KB JPEG screenshot and export PNG. The new 2.8MB PNG preserves the decoded pixels losslessly on future saves, but it does not repair JPEG blocks or create transparency.
Browser compatibility notes
Reviewed against the implementation and required web APIs on 2026-08-12. Use a current browser where these APIs are available and verify important output on your device.
- Chrome / Edge (current desktop)
- Requires local decode, canvas, encoding, Blob download, and enough memory; verify the downloaded image.
- Firefox (current desktop)
- Uses the same standard local APIs; color rendering can differ slightly from Chromium.
- Safari (current desktop)
- Uses canvas and Blob downloads; available memory and codec behavior remain WebKit-controlled.
A tool-specific question
Will the PNG become transparent?
No. Converting stores the decoded opaque JPEG pixels in PNG; it does not infer a background mask.