Add image files to start batch conversion.
Convert your image files easily with this advanced, browser-native Batch Image Converter. This free online tool allows you to upload multiple files in formats such as JPG, JPEG, PNG, WebP, BMP, GIF, SVG, or ICO and convert them simultaneously to WebP, PNG, JPEG, BMP, GIF, or ICO. Best of all, the entire process is handled locally in your browser, guaranteeing total security and privacy.
Whether you need to convert heavy screenshots to modern WebP files for faster web loading, format photo folders for social uploads, or resize multiple assets to thumbnail resolutions, our tool handles the heavy lifting in seconds without bloating your server or device.
How to Use the Batch Image Converter
- Drag and drop your images into the designated dashed upload box or select files manually.
- Choose your target output format from the Convert to format dropdown.
- Select a Resolution scale to resize outputs if you want to optimize file sizes.
- Type an optional filename prefix to rename all files in the batch automatically.
- Click Convert All Uploaded. The tool will process each file in the queue.
- Review the converted sizes and click Download All to download all converted images sequentially, or download them individually.
Understanding Modern Image Formats
WebP (Google Web Picture)
WebP provides superior compression limits for web design. It supports both lossy and lossless formats, and maintains transparency just like PNG but at a file size that is typically 25% to 35% smaller. Excellent for improving Core Web Vitals on blogs.
PNG (Portable Network Graphics)
PNG is a lossless raster format designed to replace GIF. It is perfect for icons, flat graphics, charts, and digital assets where transparent backgrounds and crisp edges are required without any compression artifacts.
JPEG / JPG (Joint Photographic Experts Group)
JPEG is the standard format for photographs and complex color gradients. While it does not support transparent layers, its lossy compression engine shrinks files dramatically, making it a reliable format for photography blogs.
Advanced Features of the Bulk Converter
- Supports input formats including JPG, PNG, WebP, SVG, BMP, GIF, and ICO.
- Automatic white background fill for transparent inputs when converting to JPEG.
- Saves storage calculations dynamically to show you exact file bytes saved.
- Original, 75%, 50%, and 25% resolution rescaling dropdown controls.
- Custom filename renaming prefix option.
- Maximum 100% quality output compression limit locked internally for lossless conversion clarity.
- Sequenced download triggers with small browser-friendly delays to prevent blocked downloads.
Frequently Asked Questions
How do I convert multiple images at once?
Simply upload up to 50 images in the upload area, select your target output format, and click the "Convert All Uploaded" button. Once completed, you can batch download them.
Are my images uploaded to any server?
No. The image conversion processes entirely on your current device using local HTML5 canvas drawing APIs. Your images are secure and never sent over the internet.
Does this image converter work on mobile phones?
Yes. The tool is fully responsive and works seamlessly on Android and iOS browsers, allowing you to convert and download photos directly on your mobile device.
Why is the JPEG output showing a white background?
The JPEG format does not support alpha transparency channels. When converting transparent images (like PNG/WebP) to JPEG, the tool automatically fills transparent regions with a white background to keep logos and charts legible.
How can I rename my converted images in bulk?
Use the "Rename prefix" control input. Enter a value like "optimized-" or "web-", and all downloaded conversion files will have this prefix attached to their names.