How to convert PNG, JPG and WebP safely in your browser
Select one supported image, choose JPG, PNG or WebP as the output, adjust quality when the selected format supports it, and convert. The browser decodes the source image and creates the new file locally, so the image itself does not need to be uploaded to FigureNest.
Which format should I choose?
JPG/JPEG is usually useful for photographs and smaller lossy files, but it cannot preserve transparency; transparent pixels are placed on white. PNG is lossless and preserves transparency, which suits screenshots, logos and graphics. WebP can preserve transparency and often produces compact web-ready files when the browser provides a reliable WebP encoder.
How the conversion works
FigureNest first validates the selected file type and decodes the image locally. The decoded pixels are drawn once onto a browser Canvas at the source image's original width and height, so this converter changes the file encoding rather than resizing the picture. Canvas then encodes those pixels into the chosen output MIME type. For JPG and WebP, the quality control is passed to the browser encoder as a value from 0.40 to 1.00; PNG uses its lossless encoder and ignores that quality slider.
When JPG is selected, the canvas is filled white before the source pixels are drawn because JPEG has no alpha channel. PNG and WebP retain transparency where the browser encoder supports it. FigureNest verifies that the returned Blob reports the requested MIME type before enabling the download, so a browser that cannot reliably create the chosen format fails instead of silently giving the file the wrong extension.
Worked example: transparent PNG to JPG
Suppose a 1200 × 800 PNG logo has transparent space around the artwork and you need a JPG for a system that accepts JPEG only. Select the PNG, choose JPG / JPEG and set quality to 85%. FigureNest decodes all 960,000 pixels locally, places a white background behind transparent areas, draws the original pixels at 1200 × 800, and asks the browser to encode a JPEG at 0.85 quality. The downloaded file keeps the 1200 × 800 pixel dimensions, but the transparent areas become white and metadata such as EXIF or an ICC profile may not survive the re-encoding. That trade-off is expected, so keep the original PNG if transparency or archival metadata matters.
Privacy, metadata and fidelity limits
The converter accepts still PNG, JPG/JPEG and WebP images and applies local file-signature and decoded-pixel safety checks. Animated WebP is rejected because browser Canvas export would otherwise keep only a still frame. Re-encoding can remove EXIF, GPS, ICC/color-profile and other metadata, so keep the original when archival metadata or exact colour management matters.
Decoded images are limited to 40 megapixels to reduce browser memory pressure, especially on phones. If the browser cannot reliably encode the requested JPG or WebP MIME type, conversion fails closed instead of offering a mislabeled file.