Quick answer
Try JPG for photos when compatibility matters, PNG for transparent graphics or sharp screenshot edges, and WebP when the destination supports it. Judge the actual file size, readability and compatibility before choosing the final export.
What each format is useful for
- JPG / JPEG is widely used for photos and continuous tones. It has no transparency; lossy encoding can create artifacts near text and sharp edges. See the MDN image format guide for format capabilities.
- PNG is useful for transparent graphics, interface screenshots and line art. Its compression is lossless, but a photo saved as PNG may become larger.
- WebP supports transparency and both lossy and lossless encoding. KitNelo re-encodes common exports, so WebP support alone does not mean every output is lossless. Check that the destination accepts it.
Convert and compare in KitNelo
- 1Open Image Conversion Studio and add the image. You can add multiple files for a batch.
- 2Select JPG, PNG or WebP to match the receiving service. Without a specified format, compare exports from the same original.
- 3Adjust quality for a lossy format. To retain transparency, preserve the original background and choose PNG or WebP.
- 4Compare downloaded bytes and inspect text, color and transparent regions in a regular viewer. For ZIP exports, also check filenames and extensions.
Three conversion misunderstandings
Converting JPG to PNG cannot restore details already lost. It saves the currently decoded image in another format. Increasing pixel dimensions likewise cannot invent detail absent from the source.
Converting PNG to JPG fills transparent regions with white because JPEG has no alpha channel. Check the background before sharing a logo intended for a dark surface.
Conversion does not guarantee a smaller file. Original compression, dimensions and output settings all affect the result. Compare the bytes of the downloaded exports.
Handle format, dimensions and bytes separately
For an application photo, first confirm that JPG is accepted, then set the required dimensions and finally compress to the byte limit. For a web illustration, decide whether transparency matters before comparing acceptable formats.
Image Conversion Studio processes a decoded single frame of animated inputs and does not preserve their animation. Exports are re-encoded and remove common original metadata. Keep originals if animation or camera information matters.
For a 200 KB submission limit, continue with the target-size compression checks. For HEIC phone originals, first follow the HEIC-to-JPG conversion workflow to obtain an accepted format.
Common questions
Are JPG and JPEG different?
They normally refer to the same JPEG format with different filename extensions. Use the suffix required by the receiving service and keep it consistent with the actual encoding.
Can I rename WebP to JPG?
Renaming does not convert image content. Decode the input and export it as JPEG using an image converter.
Why does PNG ignore the quality slider?
Canvas PNG export does not use the JPEG/WebP quality parameter. Reduce dimensions, or change format when the destination permits it.
Further reading & sources
Put the guide into practice
Open the relevant tool, preview the result and check your exported file.
