## Why batch convert?
Converting images one by one is tedious when you have dozens or hundreds of files. Batch conversion lets you process an entire folder with a single command or upload.
## Method 1: Online tools (no install)
KaijuConverter supports multi-file upload for most image conversions. Upload up to 20 files at once and download a ZIP with all converted images.
**Best for**: occasional batch jobs, non-technical users, when you don't want to install software.
## Method 2: FFmpeg (command line)
FFmpeg is the Swiss Army knife of media conversion. To convert all JPGs in a folder to WebP:
```bash
for f in *.jpg; do ffmpeg -i "$f" "${f%.jpg}.webp"; done
```
To convert all PNGs to JPG at 85% quality:
```bash
mogrify -format jpg -quality 85 *.png
```
**Best for**: large batches, scripted pipelines, CI/CD image optimization.
## Method 3: ImageMagick
ImageMagick's `mogrify` command processes files in-place:
```bash
mogrify -format webp -quality 80 *.jpg
```
To resize and convert simultaneously:
```bash
mogrify -resize 1920x1080 -format jpg -quality 85 *.png
```
## Method 4: GUI apps
- **XnConvert** (Windows/Mac/Linux, free) — drag and drop batch conversion with filters.
- **GIMP Script-Fu** — batch processing with custom scripts.
- **Squoosh CLI** — Google's image optimizer with batch support.
## Choosing the right target format
| Source | Best target for web | Best target for archives |
|---|---|---|
| JPG | WebP | PNG |
| PNG | WebP | PNG (no change) |
| HEIC | JPG or WebP | PNG |
| TIFF | WebP or JPG | PNG or TIFF |
## Tips for best results
- Always keep original files as a backup before batch converting.
- Test on a small sample first.
- For web images, target file sizes of 50-150 KB for most use cases.
Guide