PNG to JPG Converter

What is a PNG to JPG converter?

A PNG to JPG converter re-saves PNG images in the JPG (JPEG) format. PNG is lossless, which is perfect for screenshots and logos but makes photographs very heavy; JPG uses lossy compression designed for photos, so the same picture usually becomes much smaller and is accepted by practically every website, form and email client. This free MavexTech PNG to JPG converter handles a whole batch at once, lets you pick the JPG quality, fills transparent areas with a colour of your choice and shows the size of every file before and after conversion. It runs entirely in your browser, so the images are never uploaded.

How to convert PNG to JPG

1. Add PNG files. Click the upload area or drop one or many PNG files on it. Conversion starts automatically.
2. Set the JPG quality. The slider goes from 10% to 100%. The default of 90% looks identical to the original for most images; lower values give smaller files.
3. Choose a background colour. White is the default. Pick black, or your website's background colour, if the PNG has transparent edges.
4. Check the results. Each row shows the new file name, the pixel size and the old size → new size with the percentage change. Changing quality or colour re-converts the batch automatically.
5. Download. Use the button on each row, Download all for separate files, or Download all as ZIP for one archive.

How the conversion works

Your browser decodes each PNG into raw pixels and draws them on an invisible canvas of exactly the same width and height. Before drawing, the canvas is painted with the background colour you picked. This step matters because JPG has no alpha (transparency) channel: a pixel that is 100% transparent in the PNG ends up as the pure background colour, and a half-transparent pixel is blended with it. For example, a 50%-transparent blue pixel (0, 120, 255) over white becomes roughly (128, 188, 255) – a lighter blue – while over black it becomes about (0, 60, 128).

The canvas is then encoded with the browser's built-in JPEG encoder at the quality you chose. JPEG splits the image into 8 × 8 pixel blocks, converts them into frequency data and discards fine detail the eye is least sensitive to. The quality value controls how much is discarded. The pixel dimensions never change: a 400 × 300 PNG becomes a 400 × 300 JPG, and a 3000 × 2000 PNG stays 3000 × 2000.

The percentage on each row is (new size − old size) ÷ old size × 100. A PNG of 1,600 KB that becomes a 400 KB JPG shows −75%. For simple graphics the JPG can occasionally be bigger, and the tool shows a plus sign so you can see it straight away.

When converting PNG to JPG makes sense

• Photos saved as PNG by phone screenshots, editing apps or downloads – these shrink dramatically as JPG.
• Upload forms that only accept JPG, such as many job, exam and government portals.
• Email attachments and chat apps where smaller files send faster.
• Website images where page speed matters and transparency is not needed.
• Product photos with a transparent background that need a solid white background for a marketplace listing.

Keep PNG for logos, icons, line art, text-heavy screenshots and anything that needs transparency. JPG compression produces visible fuzz around sharp edges and solid colours in those images.

Tips

• Use 85–92% quality for photos you want to keep looking perfect, and 70–80% for web thumbnails.
• If you need a file under an exact size limit, convert here first and then use Image to Specific KB, or our dedicated Resize Image to 20KB tool for exam forms.
• Reduce pixel dimensions with the Image Resizer when a photo is far bigger than it will be displayed; this saves more space than lowering quality.
• Pick the background colour to match where the image will be shown, so the former transparent edge blends in.
• Browsers may block several automatic downloads at once. If Download all only saves one file, allow multiple downloads for the site or use the ZIP button.

Limitations and notes

JPG is lossy, so converting PNG to JPG and back to PNG does not restore the original pixels – keep your PNG originals. Transparency is always replaced by the chosen colour. Animated PNGs (APNG) are converted from their first frame only. The browser re-encodes the image, so colour profiles and metadata such as EXIF text are not carried over. Very large images (tens of thousands of pixels on a side) can exceed the browser's canvas limit; the tool reports an error for such files instead of producing a broken image. The ZIP option loads the open-source JSZip library from the cdnjs CDN when you first use it; files are zipped on your device.

Frequently asked questions

Is the PNG to JPG converter free and safe to use?

Yes. It is free and works entirely in your browser. Your PNG files are converted on your own device and are never uploaded to a server.

What happens to transparent areas when I convert PNG to JPG?

JPG cannot store transparency, so transparent pixels are filled with the background colour you choose (white by default). Semi-transparent pixels are blended with that colour.

Which JPG quality should I choose?

90% is a good default that looks identical to the original for most images. Use 85 to 92% for photos you care about and 70 to 80% when file size matters more, such as web thumbnails.

Does converting PNG to JPG change the image dimensions?

No. The JPG has exactly the same width and height in pixels as the PNG. Only the file format and file size change.

Why is my JPG bigger than the PNG?

Simple graphics with large flat colours, text or very few colours compress extremely well as PNG. For such images JPG can be larger and may show blur around edges, so keeping them as PNG is usually better.

Can I convert many PNG files at once?

Yes. Add as many PNG files as you like. Each gets its own download button, and you can save them all separately or together as one ZIP file.

Is the conversion reversible?

Not fully. JPG is lossy, so turning the JPG back into PNG keeps the JPG compression artifacts and the lost transparency. Keep your original PNG files if you may need them later.

Related tools

• Image Format Converter – convert between PNG, JPG and WEBP in any direction.
• JPG to PNG – the reverse conversion, lossless.
• WEBP to JPG – for images downloaded from modern websites.
• Image Compressor – shrink JPGs further.
• HEIC to JPG – convert iPhone photos.