JPEG vs PNG: a practical rule that covers almost every case

Start with JPEG for photographs and PNG for screenshots, diagrams or transparency. If the image mixes photos and small text, export both and compare the saved files at the size people will read them.

JPEG and JPG are names for the same format. Changing the extension from .png to .jpg does not convert the image; use an image converter to create a new copy.

Choose for the content and the destination

Image you need to share	Start with	Check before sending
Photo for a website or email	JPEG	Faces, gradients, texture and file size
Screenshot containing small text	PNG	Text stays readable at the intended size
Logo with a transparent background	PNG	Transparency and edge colours on the destination background
Chart or line drawing	PNG	Thin lines, labels and any upload limit
Scan containing photos and text	Compare JPEG and PNG	Faint lettering and small print, not just the photo
Work still being edited	The editor’s native format	Keep layers and an original-quality source

The receiving app may settle the choice for you. If it accepts only JPEG, choose enough quality and resolution to keep the important detail legible.

JPEG trades detail for a smaller file

JPEG uses lossy compression. It can make a useful sharing copy of a photo, but the saving and visible changes depend on the picture and encoder. There is no fixed percentage that keeps every image looking the same.

Look closely at lettering, hair, fences and sharp colour boundaries. Low quality can leave block patterns, softened detail or ringing around edges. Small screenshots often show these changes more clearly than photographs.

In the ToolsNow converter, JPG starts at 85% quality. Try that, inspect the result, then lower the setting if the file is still too large. A quality number is an encoder setting, not a percentage of original detail retained, and numbers from different tools are not directly comparable.

Re-encoding an edited JPEG can introduce further loss. Keep the original and make new exports from it. Saving a damaged JPEG as PNG or raising its quality cannot restore detail already lost.

PNG preserves the pixels you give it

PNG’s compression is lossless: decoding restores the pixel values encoded in that PNG. Flat colours and repeated patterns often compress well, which makes it useful for interface screenshots and diagrams.

Photographs can produce much larger PNG files than acceptable JPEG copies. Compare actual downloads rather than assuming a size ratio. Also remember that lossless encoding does not undo resizing, colour conversion or other changes made before the image was encoded.

For a PDF page, PDF to images offers both formats. PNG preserves the rendered pixels, but the page is still an image: its original selectable text and vector shapes are not retained in the picture file.

Handle transparency before exporting JPEG

JPEG has no transparency channel. In the converter, choose the background under Fill transparent areas before downloading a JPG. Check light and dark edges against that colour.

PNG can keep full or partial transparency. Keep a transparent original if you will need to put the image on different backgrounds later; a flattened JPEG cannot supply that transparency again.

You can compare this with the existing transparent practice PNG. Export a PNG and a JPG with a white background, then reopen them. The PNG should keep the clear outer border; the JPG should fill it with white.

When WebP or AVIF is useful

The image workspace also offers WebP and AVIF. They can produce smaller sharing copies for a given acceptable appearance, and both support transparency. Check that the destination accepts the format: support in a browser does not mean every upload form, email app or document editor does.

The image compression tool starts with WebP at 75% quality and also offers a Compatible photo JPG preset. Compare size and appearance with the original. Changing format does not guarantee a saving, and the workspace exports a flattened still image rather than preserving animation or editing layers.

How the compression differs

Common JPEG encoding transforms small blocks of image data and reduces the precision of their detail. It can also store colour information at a lower resolution than brightness. That helps explain why fine coloured text can suffer.

PNG filters rows of pixel data and compresses the result without discarding those values. It benefits from predictable patterns, but does not have JPEG’s option to trade away detail for a smaller file.

Source

• W3C — PNG specification, including lossless compression and alpha

Last reviewed 2 October 2026.