How to Convert PNG to JPG: When and How to Switch Formats

When Does PNG to JPG Conversion Make Sense?

PNG and JPG are both ubiquitous image formats, but they are designed for fundamentally different types of content. PNG uses lossless compression and supports transparency. JPG uses lossy compression and produces dramatically smaller files for photographs and complex images.

Converting from PNG to JPG is one of the most common image conversions, and for good reason: a 5 MB PNG photograph can often become a 500 KB JPG with virtually no visible quality difference. That is a 90% reduction in file size, which translates directly to faster websites, lower storage costs, and quicker sharing.

But the conversion is not always appropriate. JPG does not support transparency, it introduces compression artifacts on sharp edges and text, and each save introduces additional quality loss. Knowing when to convert is just as important as knowing how.

This guide covers both — the decision framework and the technical execution — so you can confidently convert PNG to JPG when it makes sense and know when to keep your files in PNG.

When to Convert PNG to JPG

Convert When:

Your image is a photograph. Photographs are exactly what JPG was designed for. The lossy compression in JPG exploits the fact that small color variations in photos are imperceptible to the human eye, achieving massive compression with minimal visible impact.

File size matters. If you are optimizing images for a website, sending photos via email, or managing storage constraints, JPG's smaller file sizes are a significant advantage.

There is no transparency. If your PNG does not use its alpha channel (transparency), you are storing the image in a format with unnecessary overhead. JPG will be more efficient.

You are uploading to social media. Platforms like Instagram, Facebook, and Twitter recompress uploaded images to JPG anyway. Converting beforehand gives you control over the quality settings.

You need universal compatibility. While PNG is widely supported, JPG is truly universal — every device, application, and service handles JPG without exception.

Do Not Convert When:

The image has transparency. JPG does not support transparency. Converting a PNG with a transparent background to JPG will replace the transparency with a solid color (usually white or black).

The image contains text, logos, or sharp edges. JPG compression creates visible artifacts around high-contrast boundaries. Text becomes fuzzy, logo edges get blocky, and line art degrades noticeably.

You need to edit the image further. JPG is lossy — every save discards more data. If you plan to continue editing, keep the PNG (or your editor's native format) and convert to JPG only as the final step.

The image is a screenshot. Screenshots typically contain text, UI elements, and sharp edges — exactly the content that JPG handles poorly. Keep screenshots as PNG.

For a comprehensive comparison of when to use each format, see our PNG vs JPG guide.

Understanding the JPG Quality Slider

When converting PNG to JPG, the single most important setting is the quality level. This is typically expressed as a number from 1 to 100, where 100 is the highest quality (least compression) and 1 is the lowest quality (most compression).

Here is what different quality levels actually mean in practice:

The sweet spot for most conversions is quality 80-85. This produces files that are typically 70-85% smaller than the PNG with quality that is indistinguishable to most viewers at normal viewing distances.

How to Convert PNG to JPG

Method 1: Online Conversion

The fastest approach for individual files or small batches is our JPG converter. Simply:

1. Upload your PNG file (or drag and drop)
2. Adjust the quality slider (default 85 is recommended)
3. Download the converted JPG

For batch conversions of many files, use our image converter, which handles bulk format changes efficiently.

Method 2: Using Preview (macOS)

Every Mac has a built-in converter:

1. Open the PNG file in Preview
2. Go to File > Export
3. Change the format dropdown to JPEG
4. Adjust the quality slider
5. Click Save

Method 3: Using Paint (Windows)

Windows Paint can do basic conversions:

1. Open the PNG file in Paint
2. Go to File > Save as > JPEG picture
3. Choose your filename and location
4. Click Save

Note that Windows Paint does not give you a quality slider — it uses a fixed quality setting (approximately 85).

Method 4: Command Line (ImageMagick)

For developers and power users, ImageMagick provides precise control:

# Single file conversion
convert input.png -quality 85 output.jpg

# With additional optimization
convert input.png -quality 85 -sampling-factor 4:2:0 \
  -strip -interlace JPEG output.jpg

The flags explained:

• -quality 85 — Sets JPG quality to 85
• -sampling-factor 4:2:0 — Chroma subsampling (standard for web JPGs, saves ~15% with negligible quality impact)
• -strip — Removes all metadata (EXIF, ICC profiles) to reduce file size
• -interlace JPEG — Creates a progressive JPEG (loads gradually in browsers)

Method 5: Using Sharp (Node.js)

For programmatic conversion in web applications:

const sharp = require("sharp");

await sharp("input.png")
  .jpeg({
    quality: 85,
    progressive: true,
    mozjpeg: true, // Use MozJPEG encoder for better compression
  })
  .toFile("output.jpg");

The mozjpeg: true option uses Mozilla's optimized JPEG encoder, which produces 5-10% smaller files at equivalent quality compared to the standard encoder.

Handling Transparency

The most common gotcha in PNG-to-JPG conversion is transparency. Since JPG does not support alpha channels, any transparent areas in your PNG must be filled with a solid color.

Default Behavior

Most conversion tools fill transparent areas with white by default. This is usually fine for images on white backgrounds but can produce unexpected results for other use cases.

Specifying a Background Color

With ImageMagick, you can choose the background color:

# White background (default)
convert input.png -background white -flatten -quality 85 output.jpg

# Black background
convert input.png -background black -flatten -quality 85 output.jpg

# Custom color
convert input.png -background "#f5f5f5" -flatten -quality 85 output.jpg

The -flatten flag composites the transparent image over the background color before converting.

Batch Conversion

Converting an Entire Folder (ImageMagick)

# Convert all PNGs in current directory to JPG at quality 85
mogrify -format jpg -quality 85 *.png

# Convert to a different output directory
mkdir jpg_output
mogrify -format jpg -quality 85 -path jpg_output *.png

Converting with a Script (Bash)

For more control over the conversion process:

#!/bin/bash
# Convert all PNGs to optimized JPGs

INPUT_DIR="./png_images"
OUTPUT_DIR="./jpg_images"
QUALITY=85

mkdir -p "$OUTPUT_DIR"

for png_file in "$INPUT_DIR"/*.png; do
  filename=$(basename "$png_file" .png)
  convert "$png_file" \
    -background white -flatten \
    -quality $QUALITY \
    -sampling-factor 4:2:0 \
    -strip \
    -interlace JPEG \
    "$OUTPUT_DIR/${filename}.jpg"
  echo "Converted: ${filename}.png -> ${filename}.jpg"
done

Using Our Batch Converter

For non-technical users, our image converter supports batch uploads. Drag multiple PNG files in, select JPG as the output format, and download all converted files at once. For a full guide on batch processing workflows, see our how to batch convert files tutorial.

Metadata Handling

PNG and JPG both support metadata, but they store it differently:

Stripping Metadata for Privacy

If your PNG contains location data or other private information, strip it during conversion:

# Remove all metadata during conversion
convert input.png -strip -quality 85 output.jpg

# Or with exiftool after conversion
exiftool -all= output.jpg

Preserving Color Profiles

If color accuracy matters (photography, design work), make sure the ICC color profile is preserved. Most conversion tools preserve it by default, but verify by checking the output:

identify -verbose output.jpg | grep -i "profile"

File Size Expectations

Here are realistic file size expectations when converting PNG to JPG at quality 85:

Notice that the savings are dramatic for photographs but much smaller for text-heavy or flat-color images. This makes sense — JPG compression is optimized for the smooth color transitions found in photographs, not the sharp edges and flat areas of text and diagrams.

Advanced: Progressive JPG

Progressive JPGs load in multiple passes in web browsers — first as a blurry low-resolution version that sharpens as more data arrives. This provides a better perceived loading experience than standard (baseline) JPGs, which load top-to-bottom.

# Create a progressive JPG
convert input.png -quality 85 -interlace JPEG output.jpg

Progressive JPGs are also typically 2-5% smaller than equivalent baseline JPGs, making them a free optimization.

Most modern web servers and CDNs handle progressive JPGs correctly. For web images, always use progressive encoding.

Common Conversion Mistakes

Mistake 1: Converting at Quality 100

Quality 100 produces JPG files that can be larger than the original PNG while still being lossy. JPG at 100 is not "lossless" — it still applies lossy compression, just with the least aggressive settings. The file size savings at quality 100 are minimal, making the conversion pointless.

Mistake 2: Converting Screenshots to JPG

Screenshots contain sharp text, UI elements, and flat color areas — exactly what JPG handles worst. Keep screenshots as PNG. If file size is a concern, use PNG with maximum compression or convert to WebP (lossless mode).

Mistake 3: Not Checking for Transparency

Converting a PNG with transparency to JPG without specifying a background color leads to unexpected results — typically a black or white background where the transparent areas were.

Mistake 4: Re-converting from JPG Back to PNG

Some people convert PNG to JPG, realize they need the PNG, and convert back. This does not restore the original quality — the JPG compression artifacts are now permanently baked into the image. The "recovered" PNG will be the same quality as the JPG but with a larger file size. Always keep the original PNG.

Mistake 5: Using Too-Low Quality for Archival

If you are converting PNGs to JPGs for long-term storage, use quality 90-95. The extra file size is minimal compared to quality 80, and you preserve maximum detail for potential future use.

When to Use WebP Instead

In 2026, WebP is often a better target format than JPG for web images. WebP offers:

• 30% smaller files than JPG at equivalent visual quality
• Transparency support (unlike JPG)
• Both lossy and lossless modes
• Full browser support in all modern browsers

If your primary goal is web optimization, consider converting PNG to WebP instead of PNG to JPG. See our WebP conversion guide and what is WebP format for details.

For broader web image optimization strategies, our optimize images for website guide covers the complete workflow from format selection to delivery.

Quick Reference: PNG to JPG Conversion Settings

For the most common scenarios:

• Web photos: Quality 80-85, progressive, strip metadata, 4:2:0 subsampling
• Email attachments: Quality 75-80, resize to reasonable dimensions first
• Print preparation: Quality 95, preserve ICC profile, no metadata stripping
• Social media uploads: Quality 85-90, resize to platform requirements first
• E-commerce products: Quality 85-90, white background for transparent PNGs

Use our JPG converter for quick conversions or the image converter for batch processing with full control over quality settings.