Convert JPG to PNG Without Uploading

Most online image converters quietly upload your file to a remote server, run the conversion there, and email you back a link. For a holiday photo that may be fine. For a passport scan, medical image, screenshot of a private chat, product mockup under NDA, or anything containing faces of children, it absolutely is not.

This page is different. The JPG to PNG conversion uses the browser's built-in canvas engine — the same technology that paints every image you see on the web. We decode your JPG locally, repaint it onto a canvas, then ask the browser to re-encode it as a PNG. Both the original bytes and the converted PNG stay in the memory of the tab you have open. Nothing is sent over the network.

You can verify this yourself: open your browser's developer tools, switch to the Network tab, then convert a file. You will see zero outbound requests carrying your image data.

When you actually want JPG → PNG

• Saving a screenshot you plan to edit again — JPG re-compresses every save and dulls text edges.
• Preparing a logo, icon or diagram for a website or app.
• Sending an image to a designer who needs a lossless source.
• Avoiding the slight color shift that happens when JPG quantises gradients.
• Uploading to a platform that accepts PNG but not JPG (some Slack apps, some print services).

PNG vs JPG, in one paragraph

JPG uses lossy compression tuned for photographs. It throws away information your eye is unlikely to notice and produces small files. PNG uses lossless compression and supports an alpha (transparency) channel, so files are larger but pixel-perfect. For photos, JPG still wins on size. For anything with sharp edges, text or future edits, PNG wins on quality.