JPG vs PNG: Which Image Format Should You Use?

Choose JPG for a photo delivery workflow that accepts JPEG, and consider PNG for transparent artwork or images whose exact decoded pixels matter. The best result depends on the picture and its destination. A smaller file is useful only if it still does its job.

How JPG and PNG store an image

Typical JPG encoding is lossy. It can make photographic content convenient to share, but stronger compression may affect subtle texture, gradients, and sharp edges. Once information has been discarded, changing the extension or exporting to a different format cannot bring it back.

PNG uses lossless compression for its image data and supports an alpha channel for transparency. Lossless describes the encoding of the pixels supplied to it. It does not mean that every step before that encoding—resizing, color conversion, or decoding another format—was lossless.

The MDN image format reference documents these format properties and their use on the web.

Start with the image you have

Your image or task	A practical starting point	What to inspect
A photo for a JPEG-only form	JPG	Detail, dimensions, and the byte limit
A logo with a transparent background	PNG	Alpha edges on the actual page background
A screenshot with small text	PNG	Text legibility and file size
An existing JPG for a PNG-only workflow	PNG copy	No expectation of recovered detail

Photographs

For a photograph, make one export from the best source you have and inspect it. Repeatedly opening, editing, and saving JPEGs can introduce further loss. Keeping an editing master avoids having to work from yesterday’s compressed delivery file.

A photo already saved as PNG is not automatically wrong. Try a JPG copy when the destination permits it, then compare the result before replacing anything. If the new file is not meaningfully smaller or looks worse, there is little reason to keep that particular export.

Screenshots and diagrams

Small text and flat-color edges make compression artifacts easy to notice. PNG is a useful starting point for these images. Crop away irrelevant areas or resize the image only when the smallest text remains legible at the final viewing size.

If a form accepts only JPG, convert once and inspect the lettering. Select a quality that preserves readability rather than focusing only on the number shown by a slider.

Transparency needs an explicit decision

JPG cannot retain the transparent background of a PNG logo. Conversion has to combine the image with a background color. FormatPlease uses white by default for JPG output and offers a background setting in the image converter.

Before exporting, consider where the result will appear. A white rectangle may be appropriate in a document but conspicuous on a dark website. If transparency is required, keep PNG or consider PNG to WebP, after checking the destination accepts WebP.

Changing the background in a flattened JPG later cannot reconstruct the original transparent edges exactly. Keep the PNG source.

File size: compare exports, not extensions

Image dimensions, visual complexity, and encoder choices all affect file size. There is no honest universal percentage that describes the saving from every PNG-to-JPG conversion.

Use this quick check:

• Confirm that both exports have the dimensions you need.
• Compare their actual byte sizes.
• Examine the details that matter for the intended use.
• Check transparency and color against the target background.

If you must meet a fixed upload limit, the image compression tool can search supported JPG or WebP settings. The destination’s format requirement still comes first.

Convert without replacing your source

Use JPG to PNG when a workflow needs PNG, or PNG to JPG when it needs JPEG. Both tools process selected images in the browser, with no file upload or signup required. Download a new copy and compare it with the source.

Renaming picture.png to picture.jpg changes the name, not the encoding. Use a converter and verify that the downloaded file opens. Keep the original for metadata, further editing, or another export later.

If the destination asks for a document rather than a standalone image, use Image to PDF to collect photos or screenshots into one PDF. For a photo named .jfif, JFIF to PDF provides the same page-order and paper-size controls. Keep the source images for later editing.