Changing a filename from .png to .jpg is not image conversion. The pixels must be decoded and written using the new format. For a batch, the important question is what survives that encoding: transparent pixels, useful detail, the required dimensions, and compatibility with the next application.
Separate transparency from background removal
An alpha channel describes how transparent each pixel is. It can represent empty space around a logo, the corners of a rounded image, or the area outside a circle crop. It does not automatically identify and remove a wall, sky, or photographic background.
If your source already has a solid background, exporting PNG leaves that background in place. Image Batch’s online converter is not an AI background-removal tool. The separate Windows application includes local AI workflows on compatible hardware.
Choose an output for the next application
The batch converter writes six output formats. Their tradeoffs are different:
| Output | Transparency in this editor | Practical use and limit |
|---|---|---|
| PNG | Preserved | Transparent graphics and lossless decoded pixels; compression can optionally reduce the palette |
| WebP | Preserved | Compact web assets; requires a working browser encoder and destination support |
| JPEG | Flattened to a color | Ordinary photos and common upload workflows |
| BMP | Flattened to a color | 24-bit uncompressed output; maximum 16 million pixels |
| TIFF | RGBA pixels written | Uncompressed output; maximum 16 million pixels; other viewers handle alpha differently |
| ICO | Embedded PNG alpha | Icon output fitted within 256 × 256 pixels |
Use PNG or WebP when transparent shape boundaries need to remain reliably visible in a browser. For TIFF, test the result in the application that will consume it rather than assuming every viewer treats alpha identically.
Why JPEG has a background color
JPEG has no alpha channel. Transparent areas must be combined with an opaque color, such as white or a color matching the destination’s page. That is why the editor’s JPEG background setting has no transparent option.
Test on the final light or dark surface. A circle that looks correct on white may appear to have a white square around it on a dark page. If you need the page color to show through, export PNG or WebP instead of trying to make a transparent JPEG.
For format background, see MDN’s image format guide. For a focused photo-delivery decision, read our WebP versus JPG comparison.
Know which files can be imported
The current editor accepts JPEG, PNG, WebP, BMP, ICO, HEIC/HEIF, and AVIF that the browser can decode. HEIC/HEIF is decoded locally to its first contained still image. AVIF decoding varies by environment. TIFF is currently an output format, not an input workflow.
There is no HEIC or AVIF export, animation preservation, SVG editing, or RAW processing in the online studio. If a format is listed as input, that does not imply the same format can be chosen as output. The focused HEIC to JPG page selects a real supported conversion rather than just renaming the extension.
Review transformed pixels and metadata
Crop, resize, effects, borders, and watermarks can all change the pixels before final encoding. For a shaped crop, verify that the area outside the shape remains transparent in the chosen format. Our batch crop workflow explains how to adjust each composition separately.
Re-encoded exports normally omit source metadata. Compression’s keep-original option is an exception because it can return the untouched source, including metadata and its existing format. Check that setting when the export requirements include privacy or a specific file type.
Process the queue, open a representative downloaded file in the destination application, and inspect its type, dimensions, transparent edges, and size before exporting the full set.