PNG and JPG are the two most common image formats on the web, and they are built for opposite jobs. Knowing which one fits your image — and when to convert between them — saves storage space, fits upload limits, and keeps your images looking the way you intended.
PNG vs JPG — understanding the difference
PNG (Portable Network Graphics)
PNG uses lossless compression. Every pixel you save is the exact pixel you get back, no matter how many times you open and re-save the file. PNG also supports a full alpha channel, which means real transparency.
PNG is the right choice for:
- Screenshots, especially of text and user interfaces
- Logos, icons, and illustrations with sharp edges
- Graphics that contain text or thin lines
- Any image that needs a transparent background
- Source files you plan to keep editing
The trade-off is size. Because PNG never throws data away, a photograph saved as PNG can be several times larger than the same photo saved as JPG.
JPG (Joint Photographic Experts Group)
JPG (also written JPEG) uses lossy compression. It discards detail the human eye is unlikely to notice in order to produce dramatically smaller files. It is tuned for photographs — images with smooth gradients and millions of subtle color shifts.
JPG is the right choice for:
- Photographs from a camera or phone
- Realistic images with soft gradients and no hard edges
- Anything you need to email, upload, or store at small file sizes
The trade-off is two-fold. First, JPG has no transparency — every image is a solid rectangle. Second, each time you re-save a JPG, it loses a little more quality.
PNG vs JPG at a glance
| Feature | PNG | JPG |
|---|---|---|
| Compression | Lossless (no quality loss) | Lossy (discards detail) |
| Transparency | Yes (full alpha channel) | No (solid background) |
| File size | Larger, especially for photos | Much smaller for photos |
| Best for | Screenshots, logos, text, transparency | Photographs, gradients |
| Re-saving | Safe to edit repeatedly | Quality degrades each save |
Why convert PNG to JPG
The number one reason is file size. If you have a photograph that was saved or exported as PNG, converting it to JPG can shrink it dramatically — often by 70 to 90 percent — with no visible difference at a sensible quality setting. That matters when you are:
- Attaching photos to email, where mailboxes have size limits
- Uploading to a website, form, or platform that caps file size
- Storing thousands of images and want to save disk space
- Speeding up a web page, where smaller images load faster
The key caveat: JPG cannot store transparency. When you convert a PNG that has transparent areas, those areas have to be filled with something. The standard choice is white. So if you convert a transparent logo to JPG, you will get a white rectangle behind it. For logos, icons, and anything that needs to sit on a colored background, keep it as PNG. Convert to JPG only when the image is a full photograph with no transparency that matters.
If your goal is purely to make a PNG smaller without changing its format, an Image Compressor can reduce PNG size while keeping transparency intact.
Why convert JPG to PNG
Going the other direction is less about size and more about quality and editing.
- Lossless editing. Once an image is a PNG, you can open, edit, and re-save it as many times as you like without losing quality. JPG degrades on every save — a problem known as generation loss. If you are going to do several rounds of edits, convert to PNG first and work from there.
- Screenshots and graphics. If you somehow ended up with a JPG screenshot of text or a UI, converting to PNG stops further quality loss and keeps the remaining edges as crisp as possible.
- Adding transparency later. PNG is the format you need if you plan to cut out a background or composite the image onto another.
Two honest caveats. First, converting JPG to PNG does not restore quality that was already lost. The JPG compression is permanent; PNG simply locks in whatever is there now and prevents further loss. You cannot recover detail JPG already threw away. Second, the resulting PNG will usually be larger than the JPG it came from — sometimes much larger for photographs — because PNG stores every pixel faithfully.
When you do need to go this way, the JPG to PNG Converter handles it in one step.
How to choose JPG quality
When you save a JPG you pick a quality level, usually on a 1 to 100 scale. Higher means better-looking but bigger.
- 90 to 100 — near-perfect quality, larger files. Use when the image really matters.
- 75 to 85 — the sweet spot for most photos. Hard to tell from the original, much smaller.
- 60 to 75 — noticeably smaller, fine for thumbnails and previews.
- Below 60 — visible blocky artifacts; only for cases where size beats looks.
A good default is around 80. Try it, look at the result, and adjust only if you can see a problem or need a smaller file.
How PNG/JPG conversion works in your browser
You do not need to upload your image anywhere to convert it. Modern browsers can decode and re-encode images locally using an HTML canvas.
The conversion works like this: the browser loads your image, draws it onto an off-screen canvas, and then exports that canvas to the target format. When the target is JPG, the tool first paints a solid background (white by default) onto the canvas, because JPG has no transparency — any see-through pixels in the original are flattened against that background. When the target is PNG, the alpha channel is preserved as-is.
Because every step happens in your own browser tab, your image never leaves your device. There is no server upload, no queue, and nothing stored after you close the tab. That is the whole point of a privacy-first tool: the file you convert stays yours.
How to convert PNG to JPG (or JPG to PNG)
- Open the PNG to JPG Converter (or the JPG to PNG Converter if you are going the other way).
- Drag your image into the tool, or click to select it from your device.
- If you are converting to JPG, choose a quality level — around 80 is a safe default — and a background color for any transparent areas.
- Let the browser re-encode the image. This happens instantly on your device with no upload.
- Download the converted file. The original on your computer is untouched, so you keep both.
If you are not sure which format you ultimately need, or you want to handle several formats at once, the all-purpose Image Converter lets you switch between PNG, JPG, WebP, and more from a single page.
The short version
Use PNG when you need transparency, crisp text, or repeated editing — screenshots, logos, and graphics. Use JPG when you have a photograph and want a small file. Convert PNG to JPG to shrink photos, but remember transparency becomes a solid background. Convert JPG to PNG to lock in quality before editing, but know it will not recover lost detail and the file may grow. Whichever direction you go, doing it in your browser keeps the whole process fast, free, and private.