How to Convert Between Image Formats: JPG, PNG, WebP, AVIF

Converting images between formats is one of the most common image editing tasks. You might need to convert a PNG screenshot to JPG for smaller file size, a JPG photo to WebP for better web performance, or a batch of HEIC files from your phone to JPG for compatibility. Format conversion sounds simple — and it usually is — but there are important details that determine whether your converted image looks great or suffers from quality loss, color shifts, or lost transparency. This guide covers every common conversion scenario, the best tools for each, and the pitfalls to avoid.

Why Convert Image Formats?

Format conversion serves several purposes:

• File size reduction: Converting a PNG photo to JPG or WebP can reduce file size by 80 to 95 percent with no visible quality loss.
• Compatibility: Some platforms and applications only accept specific formats. Converting to a universally supported format ensures your image works everywhere.
• Feature requirements: You might need transparency (which requires PNG or WebP), animation (which requires GIF, animated WebP, or AVIF), or vector scaling (which requires SVG).
• Performance: Modern formats like WebP and AVIF produce smaller files than JPG and PNG, improving web performance.
• Standardization: Maintaining a consistent format across a project simplifies workflows and reduces compatibility issues.

The Most Common Conversions

PNG to JPG

This is the most common conversion. PNG photos are often 5 to 20 times larger than they need to be, and converting them to JPG at quality 80 to 85 produces a much smaller file with no visible quality loss.

Important: JPG does not support transparency. If your PNG has a transparent background, converting to JPG fills the transparent area with a solid color (usually white or black). If you need to preserve transparency, do not convert to JPG — use WebP instead.

JPG to PNG

Converting JPG to PNG does not improve quality. The information lost when the JPG was created cannot be recovered. The PNG will be larger but will look identical to the JPG. This conversion is useful only when you need a lossless working copy for editing or when a specific platform requires PNG.

JPG or PNG to WebP

Converting to WebP is the best way to reduce file size for web use. Lossy WebP at quality 80 is typically 25 to 35 percent smaller than JPG at the same visual quality. Lossless WebP is 20 to 30 percent smaller than PNG. WebP also supports transparency, so you can convert a transparent PNG to WebP without losing the transparency.

JPG or PNG to AVIF

AVIF offers even better compression than WebP. Converting to AVIF can reduce file size by 30 to 50 percent compared to JPG at similar quality. The trade-off is slower encoding and slightly less universal browser support, though support is good in 2026.

HEIC to JPG or WebP

HEIC files from iPhones and iPads are not widely supported on the web. Converting them to JPG or WebP makes them usable everywhere. Most platforms do this conversion automatically on upload, but if you are working with HEIC files locally, you need a tool that supports the format.

Any Format to SVG

You cannot convert a raster image (JPG, PNG, WebP, AVIF) to SVG automatically in any meaningful way. SVG is a vector format that stores mathematical descriptions of shapes, while raster images store pixel grids. There are tracing tools that attempt to convert raster images to vector, but the results are only good for simple graphics — photographs cannot be meaningfully vectorized. If you need an SVG, you generally need to create it as a vector from the start.

Methods for Converting Image Formats

Method 1: Online Converters

Online converters are the fastest option for one-off conversions. Upload your image, choose the target format, adjust quality settings if applicable, and download the converted file.

Best for: Occasional conversions, users who do not want to install software, quick format changes.

Steps:

1. Open an online image converter in your browser.
2. Upload your image (or drag and drop it onto the page).
3. Select the target format (JPG, PNG, WebP, AVIF).
4. Adjust quality settings if the format is lossy.
5. Download the converted image.

Tip: Look for converters that process your image locally in the browser or delete it from their servers after processing, especially for sensitive images.

Method 2: Desktop Image Editors

Desktop editors like Photoshop, Affinity Photo, GIMP, and Paint.NET all support format conversion through their Save As or Export dialogs. These give you the most control over conversion settings.

Best for: Frequent conversions, users who need fine control over quality and other settings, batch processing.

Steps in most editors:

1. Open the image in the editor.
2. Choose File > Export or File > Save As.
3. Select the target format from the format dropdown.
4. Adjust the format-specific settings (quality for JPG, compression level for PNG, etc.).
5. Save the converted file.

Method 3: Command-Line Tools

For developers and automation, command-line tools are the most efficient way to convert images, especially in bulk.

Best for: Batch conversion, automated workflows, build pipelines, developers.

Common tools:

• cwebp: Converts images to WebP. Supports both lossy and lossless modes with quality settings.
• avifenc: Converts images to AVIF with configurable quality and speed settings.
• ImageMagick: A versatile tool that converts between virtually any image format. The convert command takes an input file and an output file, and infers the target format from the output file extension.
• ffmpeg: Primarily a video tool, but it also handles image format conversion for many formats.

Method 4: Built-In OS Tools

Both Windows and macOS include basic image viewers that can convert between common formats.

macOS Preview: Open the image, choose File > Export, and select the format from the format dropdown.

Windows Photos: Open the image, click "Save As" or use the Photos app's export function to choose a different format.

These built-in tools are limited — they usually do not support modern formats like WebP and AVIF, and they offer limited control over quality settings — but they are convenient for quick JPG-to-PNG conversions.

Method 5: Batch Conversion Tools

For converting many images at once, dedicated batch conversion tools save enormous amounts of time. These tools let you select a folder of images, choose a target format and settings, and convert all of them in one operation.

Best for: Converting large numbers of images, such as a product photo catalog or a folder of screenshots.

How to Avoid Quality Loss During Conversion

Format conversion can introduce quality loss in several ways. Here is how to avoid each.

Start from a Lossless Source When Possible

If you are converting from a lossy format (JPG, lossy WebP) to another lossy format, you lose quality twice. Whenever possible, start from a lossless source (PNG, TIFF, raw camera file) and convert to the lossy format as a one-step process.

Use the Right Quality Setting

When converting to a lossy format, the quality setting determines how much information is discarded. Quality 80 is a good default for most web images. Too high and you waste file size; too low and you see artifacts. Test a few settings and pick the smallest one that looks acceptable.

Preserve Color Profiles

Color profiles (like sRGB, Adobe RGB) tell the display how to render colors. Some conversion tools strip color profiles by default, which can cause colors to look different after conversion. If color accuracy matters, make sure your conversion tool preserves the color profile or converts to sRGB (the web standard) explicitly.

Handle Transparency Correctly

When converting from a format that supports transparency (PNG, WebP) to one that does not (JPG), the transparent areas become filled with a solid color. If you need to make this conversion, first fill the transparent area with the background color you want (usually white) in an editor, then convert. If you need to keep transparency, convert to WebP or PNG instead of JPG.

Avoid Multiple Conversions

Each lossy conversion loses information. If you need to convert from JPG to WebP and then later from WebP to AVIF, you have compressed the image three times. Instead, keep a lossless master and convert directly to each target format from the master.

Batch Conversion: Converting Many Images at Once

When you have dozens or hundreds of images to convert, doing them one at a time is impractical. Batch conversion tools handle all of them in one operation.

Using ImageMagick for Batch Conversion

ImageMagick can convert an entire folder of images with a single command. To convert all PNG files in a folder to WebP at quality 80:

Use the mogrify command with the format flag set to webp and the quality flag set to 80. Point it at the folder of PNG files, and it converts each one to a WebP file with the same name.

This is extremely fast and is the standard approach for automated conversion in web development workflows.

Using Desktop Batch Tools

Desktop applications like XnConvert, IrfanView (with the batch plugin), and Adobe Bridge provide graphical interfaces for batch conversion. You select a folder of images, choose the target format and settings, and the tool processes all of them. These tools are easier to use than command-line options and offer visual previews of the settings.

Common Conversion Problems and Fixes

Problem: Colors Look Different After Conversion

This usually means the color profile was stripped or converted incorrectly. Fix it by ensuring your conversion tool preserves color profiles, or by explicitly converting to sRGB before exporting.

Problem: Transparent Areas Become Black or White

This happens when converting from PNG to JPG. JPG does not support transparency. Fix it by filling the transparent area with the desired background color in an editor before converting, or by converting to WebP instead of JPG.

Problem: File Size Is Larger After Conversion

If you converted from JPG to PNG, the file will be larger because PNG is lossless. If you converted from PNG to JPG and the file is still large, the quality setting may be too high. Try quality 80 instead of 95.

Problem: The Converted Image Looks Pixelated

This can happen if the conversion tool resized the image as well as converting it. Check that the conversion settings preserve the original dimensions, or resize deliberately to the dimensions you want.

Conclusion

Converting between image formats is a straightforward process once you understand the key principles: start from a lossless source when possible, choose the right quality setting for lossy formats, preserve color profiles, handle transparency correctly, and avoid multiple lossy conversions. For most users, an online converter is the fastest option for one-off conversions, while desktop editors and command-line tools are better for frequent or batch conversion. By following the practices in this guide, you can convert images between any formats with no unnecessary quality loss and the smallest possible file sizes.