When Converting JPG to PNG Makes Sense
JPEG is lossy and PNG is lossless, so converting from JPEG to PNG cannot restore anything the JPEG already discarded. The file will get larger, often several times larger, while looking exactly the same, which sounds like a bad trade and usually is.
It is the right move in a few specific cases: when you need transparency added, when a tool or platform only accepts PNG, or when an image will go through several rounds of editing and you want to stop the quality degrading further with each save.
How to Convert JPG to PNG
The conversion itself has no settings, because PNG is lossless, there is nothing to trade off.
- Drop your JPG files onto the box above. Several at once is fine.
- The conversion runs immediately; there is no quality setting because PNG preserves every pixel it is given.
- Expect the file to grow. A photograph converted from JPEG to PNG commonly ends up three to five times larger.
- Download the PNG files. Nothing is written over the JPGs you started with.
- If you needed transparency, add it in an image editor afterwards, converting the format makes transparency possible but does not create it.
Conversion Cannot Undo Compression
This is the point that catches people out. JPEG compression permanently removes information, and PNG simply stores whatever pixels it is handed with perfect fidelity. Converting a JPEG to PNG therefore preserves the JPEG artefacts exactly, at a much larger file size, you are storing the compression damage losslessly.
What conversion does prevent is further degradation. If you are going to edit an image across several sessions, each JPEG save re-encodes the whole picture and loses a little more. Converting to PNG first freezes the quality where it is, and you can export back to JPEG once at the end.
When to Convert and When Not To
The decision comes down to what you need the file to do next.
| Situation | Convert to PNG? | Why |
|---|---|---|
| You need a transparent background | Yes | JPEG cannot store transparency at all |
| A platform only accepts PNG | Yes | Compatibility requirement |
| Editing across multiple sessions | Yes | Stops generational loss on each save |
| Placing a photo on a web page | No | Larger file, no visible gain |
| Emailing a photograph | No | Will multiply the attachment size |
| Trying to improve JPEG quality | No | Lost detail cannot be recovered |
If the goal is a smaller file rather than a lossless one, WebP is usually the better answer than either format: it offers a lossless mode that beats PNG and a lossy mode that beats JPEG.
Screenshots Are the Exception
Everything above assumes a photograph. For screenshots, diagrams, logos and anything with flat colour and sharp edges, PNG is genuinely the better format and will often be smaller than the JPEG as well as looking better. JPEG handles hard edges poorly, producing the faint halos you see around text in a screenshot saved as JPEG.
That is worth knowing because the source format is not always the right one. A screenshot that arrived as a JPEG was saved in the wrong format to begin with, and converting it to PNG will not repair the halos, but it will stop them getting worse and is the correct format for any further editing.
PNG also has a second advantage that rarely gets mentioned: it stores an alpha channel per pixel rather than a single transparent colour, so a soft shadow or an anti-aliased edge fades out smoothly instead of leaving a hard fringe. That is why a logo exported as PNG sits cleanly on a coloured background while the same logo as a GIF shows a jagged outline.