Screenshot or photo? A worked example
PNG and JPG solve different problems. PNG stores every pixel exactly, which is ideal for screenshots, logos and text but wasteful for photos. JPG throws away detail the eye barely notices, which makes photos far smaller but leaves smudges around sharp edges. Whether converting helps depends on what is in the picture, so this guide starts there, then covers settings, transparency, size limits and when to leave a PNG alone.
Here are four common PNG files and what happens to them as JPG at the default 92 percent. The sizes are illustrative; real files vary with their content.
| Image | PNG size | JPG size | Verdict |
|---|---|---|---|
| Phone photo exported as PNG, 4032 × 3024 | About 15 to 20 MB | About 3 to 4 MB | Convert: large saving, no visible change |
| A4 scan saved as PNG at 300 DPI | About 5 to 10 MB | About 1 to 3 MB | Convert, or put it in a PDF |
| Full HD screenshot of a web page | About 300 to 600 KB | Often only a little smaller | Usually keep PNG; text edges soften |
| Logo with a transparent background | About 40 KB | Similar or larger, on a solid box | Keep PNG |
Photos and scans are full of fine noise, which lossless PNG has to store exactly and JPG can approximate cheaply. Screenshots and logos have large flat areas that PNG already compresses well, and sharp edges that JPG handles badly. So the bigger and more photographic the PNG, the more you gain.
How to convert PNG to JPG
- Drop your PNG files onto this page, press Choose files, or paste a screenshot with Ctrl+V (Cmd+V on a Mac). The free plan takes 50 files per batch.
- JPG is already selected. Set Quality: 92 percent for photos, 95 percent or higher for anything with text.
- Pick a Background colour for transparent areas. White is the default.
- If the destination has a kilobyte limit, turn on Also limit file size and type it.
- Press Convert, drag the Compare before and after slider over any text to check it, and download the files one by one or as a ZIP.
Quality for screenshots and graphics
When a screenshot must be JPG, for example because a support form only takes JPG, raise the quality rather than lowering it. JPG works in small blocks, and the faint ringing it leaves around black text on white is most visible at lower settings. At 95 to 100 percent text stays crisp, at the cost of a file that may be close to the PNG in size.
For photos the opposite applies: 85 to 92 percent is visually identical to the PNG, and anything above that mostly adds bytes.
Transparency: white, black or another colour
JPG has no transparency at all. Every transparent pixel must become a real colour, and the converter uses the Background colour you choose. If you have seen transparent PNGs turn black in other tools, that is because they dropped the transparency without filling it; here the fill is always the colour shown in the picker.
Logos and cut-out photos usually have soft, semi-transparent edges. Those edge pixels are blended with the background colour, so a logo flattened onto white and then placed on a dark page shows a pale outline. Pick the colour of the page or slide the image will sit on, and the edges blend in cleanly.
Flattening cannot be undone. Converting the JPG back to PNG will not restore transparency, so keep the original PNG.
Hitting a size limit
With Also limit file size on, the converter searches for the highest JPG quality that fits under your limit. It will not go below 45 percent quality while it can still reduce the dimensions instead, because heavy blocks look worse than slightly fewer pixels. A 4032 × 3024 photo squeezed under 100 KB will therefore come out with much smaller dimensions; a small screenshot under the same limit may keep its full size.
If the portal also asks for exact pixel dimensions, use Resize image instead, which can set the dimensions and the size limit in one pass.
Other things that change
- Colour: the JPG is written as standard sRGB without an embedded profile, and 16-bit PNGs are reduced to 8 bits per channel.
- DPI: a print resolution stored in the PNG is not carried over. If a portal checks for 300 DPI, set it afterwards with Change DPI, which does not touch the pixels.
- Metadata: text and camera information stored in the PNG is removed.
- Animated PNGs: only the first frame is converted.
When to keep the PNG
- Logos, icons and anything you will place on different backgrounds.
- Screenshots of code, spreadsheets and interfaces, where sharp text matters more than size.
- Images you are still editing. Each JPG save loses a little more detail, while PNG can be saved again and again unchanged.
- Images for your own website: WebP keeps transparency and is usually smaller than both.
Converting locally versus uploading
Screenshots often show things you would rather not send to a stranger's server: messages, account pages, documents. With an upload-based converter every file makes a round trip; here the PNG is decoded and re-encoded inside your browser and nothing leaves the device, so a batch starts at once instead of waiting on your upload speed. Free batches take 50 files of up to 200 MB; Pro takes 500 files of up to 1 GB and works offline in the installed app.