Batch image converter: help & limits

About this tool

Bring a mixed set of image formats together in one pass. Choose up to ten images, pick JPG, PNG or WebP, and review each converted result. Download the files individually or collect successful results in a ZIP. A damaged or unsupported image gets its own explanation, so you can still keep the rest of the set.

How to use

Choose up to ten images within the displayed limits.
Pick one output format. Open Adjust quality only if you want a different JPG or WebP setting, then choose Convert images.
Review previews and file details. Download individual images, or choose Download ZIP.

Supported files

Still JPG, PNG, WebP, AVIF, BMP, still GIF and supported HEIC. Up to 20 files, 128 MiB combined; 64 MiB per image, or 32 MiB per HEIC (maximum 10 HEIC). 64 megapixels each. Up to twenty images per batch. Maximum 16,384 pixels per edge and 128 MiB output.

How it works

The queue decodes and re-encodes one image at a time in a local worker. HEIC uses a bundled WebAssembly decoder; AVIF needs native browser support. Each output is checked for the requested format and dimensions. A separate worker packages completed files into a ZIP without recompressing them. Duplicate output names receive numeric suffixes.

Examples

Product photos in one format

Select three JPG photos and two transparent PNGs, then choose JPG. All five outputs retain their pixel dimensions; transparent areas become white. A ZIP collects the completed copies.

Two photos with the same name

Select two files both named photo.heic and choose PNG. Successful outputs are named photo-converted.png and photo-converted-2.png, so neither overwrites the other inside the ZIP.

Limitations

Images are processed sequentially, not all at once. Combined output is capped at 128 MiB; low-memory devices may fail below the limits. ZIP assembly temporarily requires additional memory.
Still images only. Animated PNG/WebP, HEIF sequences, multiple-image HEIC and HEIC with alpha are rejected. AVIF decoding depends on the browser and file variant.
JPG replaces transparency with white. JPG and WebP are lossy; PNG can be much larger. Embedded metadata, HDR and exact color-profile behavior are not preserved as a guarantee.
Cancel keeps finished results, but leaving the page or starting over clears the set. ZIP creation is separate from conversion and does not automatically save a file.

Privacy

Selected images, filenames and outputs remain in browser memory. Reqly sends none of them to a server and saves nothing in browser storage. Start over or leave the page to release this session’s references. Files you download remain on your device until you remove them.

Local processing explained

Common questions

Can I mix HEIC, AVIF and PNG in one set?

Yes, within the limits, if the files use supported still-image variants. HEIC is limited to five images per batch. An AVIF your browser cannot decode gets an error without being uploaded.

What happens if one image fails?

The queue continues with the others. Successful outputs remain available for individual download or ZIP. Retry remaining repeats unfinished files with the same settings.

Does the ZIP make my images smaller?

No. It groups already encoded images into one download. Choose a suitable output format and quality to change the image file sizes.