Convert PNG to JPG
PNG files are lossless, which makes them large: a photo saved as PNG is often five to ten times the size of the same photo as JPG. This tool re-encodes each PNG as a JPG at the quality you choose and lets you pick the colour that replaces transparent pixels. Everything happens on your device.
How to use the PNG to JPG
- Drop your PNG files, or click the box to browse. Screenshots can be pasted with Ctrl+V.
- Set the JPG quality. The default of 90 keeps photos looking identical.
- If your PNGs have transparent areas, pick the colour that should replace them.
- Click Convert, then download each JPG or all of them as a ZIP.
What you gain and what you lose
PNG stores every pixel exactly as it was, using lossless DEFLATE compression. That is perfect for screenshots, logos and anything with flat colour, but wasteful for photographs, where no two neighbouring pixels are identical. JPEG throws away detail your eye is least sensitive to — mostly fine colour variation — and typically produces a file 80–90% smaller for the same photograph.
Three things do not survive the conversion. Transparency is the obvious one: JPEG has no alpha channel, so every transparent pixel is painted with the background colour you choose (white by default, which is right for most documents, and black or your brand colour when the image sits on a dark page). Sharp edges are the second: JPEG compresses in 8×8 pixel blocks, so text, screenshots and line art pick up faint halos known as ringing. Metadata is the third: because the file is redrawn on a canvas, text chunks and any embedded colour profile are dropped and the output is plain sRGB.
When to convert and when not to
| Image | Convert to JPG? | Why |
|---|---|---|
| Photograph saved as PNG | Yes | Usually 5–10× smaller with no visible difference at quality 90. |
| Screenshot with text | No | JPEG blurs small text. Keep PNG, or use WebP. |
| Logo with transparency | Only if the background is fixed | The transparent area becomes a solid rectangle. |
| Scanned document | Yes, at quality 85+ | Large savings, and forms almost always accept JPG. |
Choosing a quality value
Quality is not a percentage of visual fidelity; it is a knob on the quantisation tables. In practice 90 is the safe default for anything you might print or crop later, 80 is right for web pages and email, and 70 is the lowest most people would accept for a photo. If you need a specific file size rather than a specific quality, use the image compressor, which searches for the highest quality that fits your limit.
A worked example
A 1920 × 1080 screenshot of a photograph weighs about 4.1 MB as a 24-bit PNG. At quality 90 the JPG is roughly 420 KB; at quality 80, about 240 KB. The same 1920 × 1080 screenshot of a spreadsheet goes from 180 KB as PNG to 260 KB as JPG — larger, and blurrier. That is the whole rule in one example: photographs win, flat graphics lose.
Frequently asked questions
Will the JPG look worse than my PNG?
At quality 90 the difference is invisible on a screen for photographs. For screenshots, logos or text, JPEG adds visible halos around edges and PNG is the better choice.
What happens to transparent parts of the PNG?
They are filled with the colour you pick in the options, because the JPEG format has no transparency at all. White is the default.
Can I convert hundreds of PNGs at once?
Up to 100 files per run here. All of them are processed on your device and can be downloaded as a single ZIP.
Does the tool upload my images?
No. Decoding and encoding both use your browser. You can disconnect from the internet after the page loads and it still works.
Why is my converted file bigger than the PNG?
That happens with flat graphics, screenshots and line art, where PNG compression is already very efficient. Keep the PNG, or try WebP instead.
Privacy
This tool runs entirely inside your browser using WebAssembly and the Canvas/File APIs. Your files are never uploaded to ToolFlint or any third party; you can verify this in your browser's network tab or by switching to airplane mode after the page loads. Read how we process files.
Last updated 2026-09-23.