Choosing the right format
Image formats are not interchangeable, and picking the wrong one either wastes bandwidth or damages quality. The choice comes down to what the image contains.
JPEG
JPEG is designed for photographs. Its compression works by discarding fine colour detail the eye struggles to perceive, which is extremely effective on the smooth gradients and organic textures found in photographs. Files are small and universally supported.
It has two significant limitations. It cannot store transparency, so any transparent area must be filled with a solid colour — which is why this converter offers a background colour option. And because compression is lossy, it handles sharp edges poorly, producing visible halos around text and line art.
PNG
PNG uses lossless compression, so nothing is discarded and the image can be re-saved indefinitely without degrading. It supports full alpha transparency, including partial transparency, which makes it the standard for logos, icons and any image that needs to sit over a variable background.
It is the right choice for screenshots, diagrams, charts and anything containing text, where crisp edges matter more than file size. Used for a photograph, however, PNG produces files several times larger than JPEG for no visible benefit.
WebP
WebP was developed to replace both. It supports lossy and lossless compression, handles transparency, and produces files roughly twenty-five to thirty percent smaller than JPEG at equivalent quality. Every current browser supports it.
The remaining argument against WebP is compatibility outside the browser. Some older desktop software, printing workflows and third-party platforms still do not accept it. For anything that will only be viewed on the web, it is the better choice; for a file you are sending to someone else, JPEG or PNG remains safer.
Converting without losing quality
Some conversions lose information irreversibly. Converting JPEG to PNG does not restore what the JPEG discarded — it simply stores the already-degraded image losslessly, in a much larger file. Converting PNG to JPEG discards transparency and applies lossy compression permanently.
Where possible, convert from the highest-quality original you have rather than from an intermediate copy, and keep the original in case you need a different output later.
Processed locally
Conversion is performed by drawing your image to a canvas in your browser and re-encoding it there. Nothing is uploaded, so private photographs, client work and confidential screenshots stay on your device.
Frequently Asked Questions
What happens to transparency when converting to JPG?
JPEG cannot store transparency, so transparent areas are filled with the background colour you select, white by default.
Does converting JPG to PNG improve quality?
No. The data JPEG discarded is gone permanently. You get a larger file containing exactly the same visible image.
Which format is best for a website?
WebP for most purposes, since it is smallest at equivalent quality. Use PNG where you need transparency and maximum compatibility, and JPEG for photographs shared outside the browser.
Can I convert several images at once?
Yes. Select or drag multiple files and each is converted with its own download link.
Are my images uploaded?
No. Conversion happens entirely in your browser using the canvas API.