Format should follow the image
JPEG remains useful for photographs and broad browser compatibility. PNG is a good fit for lossless graphics and transparency. WebP handles photographs and transparency with efficient compression in current browsers. The converter offers these three outputs because they cover common web and office tasks.
Conversion is a new encoding
The browser decodes the source into pixels, draws those pixels to a canvas and encodes a new file. Metadata such as camera details is not carried across. Animated sources become a still frame. Converting a JPEG to PNG does not restore detail already removed by JPEG compression.
Transparency needs attention
PNG and WebP can keep transparent pixels. JPEG cannot. When JPEG is selected, the tool places white behind transparent areas instead of allowing them to become black or unpredictable. Check logos, shadows and cut-out product images carefully in the preview.
Compare bytes and appearance
A newer format can produce a smaller result, but not for every image. Flat graphics, noisy photographs and screenshots behave differently. Review the output size and the visible result. Keep the format that meets the destination's support, clarity and size requirements.
Nothing is uploaded
Reading, drawing and encoding happen with local browser APIs. The selected image is not sent to a conversion server. Available input support depends on the browser, so an uncommon format may need a desktop editor before it can be converted here.
Keep the source and test the destination
Conversion creates a new file, so preserve the original as the editable master. Open the result in the application, content system or browser where it will be used. Some older software accepts JPEG or PNG but not WebP, while modern websites can normally serve WebP with a fallback when needed. If colour appearance is critical, compare it on the target device because browser canvas export may not preserve every embedded colour profile or metadata field. The correct format is the one that balances compatibility, transparency, visible quality and transfer size for that particular use.
Why the format list is short
TIFF, HEIC and many specialist formats have valid uses, but browser reading and encoding support varies. The main choices stay with JPEG, PNG and WebP. AVIF appears only when the current browser proves that it can create a valid AVIF output. A shorter list keeps the choice understandable. Use a desktop conversion workflow when archival requirements, print production or an uncommon destination specifies another format.