Your files never leave your device. All processing happens in your browser.
Open the Img Stop Bulk Image Converter, add your images or a folder, choose JPG, PNG, WebP or AVIF and click Convert all. Every file – including HEIC, GIF and BMP – is converted on your device and you download the results as one ZIP.
About the Bulk Image Converter
The Img Stop Bulk Image Converter changes the format of large batches of images in one step. Convert iPhone HEIC photos to JPG, WebP downloads to JPG or PNG, PNG screenshots to WebP, or anything to the modern AVIF format.
Mixed batches are no problem: drop a folder with different formats and they all come out in the format you choose. Transparent areas get the background color you pick when converting to JPG. Nothing is uploaded, so converting hundreds of images is fast and private.
Key features
- Any to JPG, PNG, WebP, AVIFMixed formats in, one format out.
- HEIC supportConvert iPhone HEIC/HEIF photos in bulk.
- Quality controlChoose the quality for JPG, WebP and AVIF.
- Transparent to JPGPick the background color for transparent areas.
- Keeps file namesOnly the extension changes – or use your own naming pattern.
- Folder in, ZIP outConvert a whole folder and download one ZIP.
How to use the Bulk Image Converter
- Add images Drop images or a folder of mixed formats on the box.
- Choose the format Pick JPG, PNG, WebP or AVIF and set the quality.
- Convert Click Convert all and follow the progress.
- Download Download the ZIP or save the converted files into a folder.
Bulk Image Converter at a glance
| Price | Free, no sign up, no watermark |
|---|---|
| Number of images | No fixed limit – hundreds at once |
| Input formats | JPG, PNG, WebP, HEIC, AVIF, GIF, BMP, SVG |
| Output | JPG, PNG, WebP or AVIF |
| Download | One ZIP, single files, or straight into a folder |
| Processing | In your browser – files are not uploaded |
When to use it
- Turn a folder of iPhone HEIC photos into JPGs that open on any PC.
- Convert WebP images saved from websites into JPG or PNG.
- Switch a website image library to WebP or AVIF for faster loading.
- Convert PNG screenshots to small JPG files for sharing.
- Standardise mixed product images into one format.
Tips for the best result
- Choose JPG at 85–90% for photos that need to open everywhere.
- Choose WebP for websites – it is usually 25–35% smaller than JPG.
- Keep PNG for logos and graphics with transparency.
- AVIF gives the smallest files but older software may not open it.
Frequently asked questions
Can I convert many HEIC photos to JPG at once?
Yes. Add all your HEIC photos or the folder that contains them, choose JPG and click Convert all. They are decoded and converted in your browser.
Will the file names stay the same?
Yes, by default only the extension changes. You can also use a naming pattern such as image-{n} or {date}-{n}.
What happens to transparent PNGs when I convert to JPG?
JPG cannot store transparency, so transparent areas are filled with the background color you choose – white by default.
Is there a limit on the number of files?
No fixed limit. Large batches are converted one after another on your device.
Are my images uploaded?
No. Conversion happens entirely in your browser.
Learn more
- web.dev: Image performance – why smaller images make pages faster
Last updated October 30, 2026 by the Img Stop team.