Image Format Conversion Guide

Converting between image file formats is a common task when preparing images for different purposes. Whether you’re optimizing for web, preparing for print, or ensuring compatibility, understanding format conversion helps you make the right choices.

This guide covers when to convert, which formats to choose, and how to maintain quality during conversion. For an even more comprehensive walkthrough covering every major format pair, see our complete image format conversion guide.

Why Convert Image Formats?

Common Reasons for Conversion

Web optimization:

• Convert large TIFFs to compressed JPEG or WebP
• Convert PNG screenshots to JPEG for smaller file size
• Convert to WebP for best compression with quality

Print preparation:

• Convert JPEG to TIFF for professional printing
• Convert RGB to CMYK color mode

Compatibility:

• Convert HEIC (iPhone photos) to JPEG for universal support — our HEIC to JPG guide covers this common workflow in detail
• Convert WebP to JPEG for older browsers
• Convert RAW to working formats for editing

Transparency needs:

• Convert JPEG to PNG when transparency is required
• Convert GIF to PNG for better quality with transparency

File size reduction:

• Convert PNG photos to JPEG (photos don’t need PNG)
• Convert uncompressed BMP to compressed formats (our BMP conversion guide covers the best migration paths)

Understanding Format Characteristics

Lossy vs. Lossless

Lossy formats (JPEG, WebP lossy):

• Discard some data to reduce file size
• Quality degrades with each save
• Best for photographs where exact pixels don’t matter

Lossless formats (PNG, TIFF, WebP lossless):

• Preserve all original data
• Can be edited repeatedly without degradation
• Larger files than lossy equivalents

Format Comparison

Format	Compression	Transparency	Animation	Best For
JPEG	Lossy	No	No	Photos, web images
PNG	Lossless	Yes	No	Graphics, screenshots, transparency
WebP	Both	Yes	Yes	Web (modern browsers)
GIF	Lossless	Yes	Yes	Simple animations
TIFF	Both	Yes	No	Print, archival
BMP	None	No	No	Legacy Windows use

When to Convert

JPEG to PNG

Convert when:

• You need transparency
• Image has sharp edges, text, or graphics
• You’ll be editing the image multiple times

Don’t convert when:

• The original JPEG quality is already low
• File size matters and transparency isn’t needed

PNG to JPEG

Convert when:

• The image is a photograph
• Transparency isn’t needed
• File size is a priority

Don’t convert when:

• Image has sharp text or line art
• Image needs transparency
• You need to edit the image further

To WebP

Convert when:

• Images are for modern web browsers
• You want best compression with quality
• You need both photos and graphics in one format

Don’t convert when:

• Supporting very old browsers
• Preparing for print

To TIFF

Convert when:

• Preparing for professional printing
• Archiving important images
• Working in professional editing software

Don’t convert when:

• Images are for web use only
• Storage space is limited

Conversion Best Practices

Preserve Originals

Always keep your original files:

• Never overwrite originals with converted versions
• Store originals in a separate folder
• Convert from originals rather than from previously converted files

Choose Appropriate Quality Settings

For JPEG:

• 80-85% quality: good balance for web
• 90-95% quality: high quality, larger files
• Below 70%: noticeable quality loss

For WebP:

• 75-80% quality: excellent for web
• 85-90% quality: near-lossless appearance

Avoid Multiple Lossy Conversions

Each save in a lossy format degrades quality:

• JPEG → edit → JPEG → edit → JPEG = cumulative loss
• Keep working files in lossless format (TIFF, PNG, PSD)
• Convert to JPEG only for final output

Match Resolution to Purpose

For web:

• 72-96 PPI is standard
• Actual pixel dimensions matter more than PPI
• 1200-2000px on longest edge typically sufficient

For print:

• 300 DPI at print size
• Larger pixel dimensions needed

How to Convert

Using BulkImagePro

BulkImagePro handles batch format conversion:

• Convert between JPEG, PNG, and WebP
• Process up to 50 images at once
• Maintain quality during conversion
• No software installation required

Conversion workflow:

1. Upload images to BulkImagePro
2. Select target format
3. Adjust quality settings if available
4. Download converted files

Using Desktop Software

Adobe Photoshop

1. File → Export → Export As
2. Select format from dropdown
3. Adjust quality and options
4. Export

For batch conversion: File → Scripts → Image Processor

GIMP (Free)

1. File → Export As
2. Change file extension to target format
3. Adjust format options
4. Export

ImageMagick (Command Line)

# Single file
convert input.png output.jpg

# Batch conversion
mogrify -format jpg *.png

# With quality setting
convert input.png -quality 85 output.jpg

Online Tools

Various online converters work for single images:

• Quick access without software
• Privacy considerations for sensitive images
• Often limited to one file at a time

Format-Specific Considerations

Converting to JPEG

Settings to adjust:

• Quality level (typically 80-90%)
• Color profile (sRGB for web)
• Progressive vs. baseline encoding

What changes:

• Transparency becomes white (or specified color)
• Subtle gradients may show banding
• Sharp edges may show artifacts

Converting to PNG

Settings to adjust:

• Bit depth (8-bit vs. 24-bit)
• Interlacing (for progressive loading)
• Compression level (doesn’t affect quality)

What changes:

• File size increases for photos
• All detail is preserved

Converting to WebP

Settings to adjust:

• Quality level
• Lossy vs. lossless mode
• Effort/speed tradeoff

What changes:

• Smaller files than JPEG/PNG at equivalent quality
• Limited support in very old browsers

Batch Conversion Tips

Organizing Files

Before batch conversion:

• Group similar images (photos vs. graphics)
• Separate by target use (web, print, social)
• Create output folders to keep organized

Quality Consistency

For consistent results:

• Apply the same settings across batches
• Use presets when available
• Test on a few images before processing all

Verification

After batch conversion:

• Spot-check representative images
• Verify file sizes are as expected
• Confirm dimensions weren’t inadvertently changed

Common Conversion Mistakes

Converting Low-Quality JPEG to PNG

Problem: PNG won’t restore lost JPEG quality Solution: Source from originals when possible

Excessive Compression

Problem: Over-compressed images look poor Solution: Use quality 80%+ for visible images

Wrong Format Choice

Problem: Using JPEG for graphics with text Solution: Match format to image content

Losing Transparency

Problem: Converting PNG with transparency to JPEG Solution: Use PNG or WebP when transparency needed

FAQ

Does converting JPEG to PNG improve quality?

No. Converting lossy to lossless doesn’t restore lost data. The PNG will be larger but not higher quality than the JPEG source.

What format should I use for web images?

WebP offers the best compression with quality for modern browsers. JPEG works universally for photos. PNG for graphics with transparency or sharp edges.

Will converting images reduce file size?

Depends on the conversion. JPEG typically produces smaller files than PNG for photos. WebP is smaller than both. Converting from JPEG to PNG increases size.

Can I convert RAW files?

Yes, but RAW files should typically be processed first in software like Lightroom or Capture One, then exported to the target format.

What happens to metadata during conversion?

Depends on the tool and settings. Most tools preserve basic EXIF data. Some strip metadata for privacy or file size. Check your tool’s options.

Should I convert images before or after editing?

After editing, convert to final format. Keep working files in lossless format (TIFF, PSD, or native editor format) during editing.

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Need to convert multiple images at once? Try BulkImagePro — batch convert between JPEG, PNG, and WebP. Process up to 50 images while maintaining quality.