Every image format serves a different purpose. JPG is ideal for photographs, PNG preserves transparency and sharp edges, and WEBP delivers smaller file sizes for the web. Knowing how to convert between these formats saves storage space, speeds up your website, and ensures your images look their best wherever they appear.
In this guide, you will learn exactly when and how to convert images between PNG, JPG, and WEBP using free online tools. Whether you need to prepare images for a website, optimize photos for email, or convert a batch of files at once, this walkthrough covers everything you need.
Understanding Image Formats: PNG vs JPG vs WEBP
Before converting anything, it helps to understand what makes each format unique. Choosing the right format from the start can save you time and produce better results.
JPG (JPEG)
JPG uses lossy compression, which means it discards some image data to reduce file size. This makes it perfect for photographs and images with millions of colors. The trade-off is that each time you save a JPG, it loses a tiny bit of quality. JPG does not support transparency, so any transparent areas become white or another solid color.
PNG
PNG uses lossless compression, preserving every pixel of the original image. It supports full transparency (alpha channels), making it the go-to format for logos, icons, screenshots, and graphics with text. The downside is that PNG files are typically much larger than JPG files, especially for photographs.
WEBP
WEBP is a modern format developed by Google that supports both lossy and lossless compression. It produces files that are 25-35% smaller than equivalent JPGs and PNGs while maintaining comparable quality. WEBP also supports transparency and animation. Most modern browsers support WEBP, making it an excellent choice for web images.
When to Convert Between Formats
Converting between formats is not just a technical exercise. There are practical situations where switching formats makes a real difference.
- PNG to JPG: When you have a photograph saved as PNG and the file size is too large. Converting to JPG can reduce the file by 60-80% with minimal visible quality loss.
- JPG to PNG: When you need to add transparency to an image, or when you are working with screenshots and graphics that have sharp text and lines.
- PNG or JPG to WEBP: When you are optimizing images for a website and want to reduce page load times without sacrificing visual quality.
- WEBP to JPG or PNG: When you need to share an image with someone whose software does not support WEBP, or when uploading to a platform that only accepts traditional formats.
How to Convert Images Online Step by Step
You do not need to install any software to convert image formats. The ConvertKr Image Converter handles all conversions directly in your browser, and your files never leave your device.
Step 1: Upload Your Image
Open the converter tool and drag your image onto the upload area, or click to browse your files. The tool accepts PNG, JPG, WEBP, BMP, GIF, TIFF, and several other formats. You can upload a single image or multiple images at once for batch conversion.
Step 2: Choose Your Output Format
Select the format you want to convert to. If you are converting to JPG or WEBP, you will see a quality slider. A quality setting of 80-85% is usually the sweet spot for photographs, offering significant file size reduction with virtually no visible quality loss. For images where every detail matters, set the quality to 95% or higher.
Step 3: Download the Converted File
Click the convert button and your new file will be ready to download in seconds. For batch conversions, you can download all files as a ZIP archive. The original file remains untouched, so you always have a backup.
Quality Settings and What They Mean
When converting to lossy formats like JPG and WEBP, the quality slider controls how much compression is applied. Here is a practical breakdown of what different quality levels produce.
- 100%: Maximum quality, largest file size. Essentially lossless for JPG. Use this only when you need archival quality.
- 85-95%: Excellent quality with noticeable file size reduction. Ideal for portfolio images, product photos, and print-ready files.
- 70-85%: Good quality with significant file savings. Perfect for blog posts, social media, and general web use. Most viewers cannot tell the difference from the original.
- 50-70%: Acceptable quality for thumbnails, previews, and situations where file size is more important than pixel-perfect accuracy.
- Below 50%: Visible compression artifacts. Only use this when extreme file size reduction is absolutely necessary.
Batch Converting Multiple Images
If you have dozens or hundreds of images to convert, doing them one at a time is impractical. Batch conversion lets you process all your files in a single operation.
Preparing Your Files
Organize the images you want to convert into a single folder on your computer. This makes it easy to select them all at once. Remove any files you do not want to convert to avoid processing unnecessary images.
Using Batch Conversion
With the image format converter, select all the files you want to convert. Choose your target format and quality settings. The tool will process each image and provide a download link for the entire batch. This approach can save hours of manual work when you are migrating a website or preparing a large photo gallery.
Tips for Getting the Best Results
Converting between formats is straightforward, but a few best practices will help you get the most out of each conversion.
- Always keep your original files. Conversion is often a one-way process in terms of quality. Store your originals in case you need to convert again later with different settings.
- Avoid converting JPG to JPG. Each time you re-encode a JPG, it loses quality. If you need to edit a JPG, do your work and save only once at the end.
- Use WEBP for web content. If your audience is using modern browsers, WEBP delivers the best balance of quality and file size. You can always provide JPG fallbacks for older browsers.
- Match the format to the content. Use JPG for photos, PNG for graphics and screenshots, and WEBP when file size is a priority.
- Combine conversion with compression. After converting, run your images through an image compressor to squeeze out additional file size savings without further quality loss.
Converting images between formats does not have to be complicated. With the right tool and a basic understanding of when to use each format, you can optimize your images for any purpose in just a few clicks.