Which formats can it read and write?

It writes JPG, PNG, WebP and AVIF, and reads whatever your browser can decode — which covers JPG, PNG, WebP, AVIF and GIF, plus TIFF in some browsers. Camera raw files are not supported; export those from your editor first.

Do converted files keep their metadata?

Re-encoding produces a new file, so embedded metadata is not carried across. Convert first, then run the batch through the metadata embedder to write titles and keywords into the finished files.

Is there a file or batch size limit?

The practical limit is your machine's memory rather than a fixed number, since everything is decoded locally. Very large batches of high-resolution files are best run a few hundred at a time.

Will converting to JPG hurt image quality?

JPG is lossy, so some data is always discarded. At a high quality setting the difference is invisible at normal viewing sizes, but avoid repeatedly converting an already-compressed JPG, because each pass compounds the loss.

Does anything leave my computer?

No. Decoding, resizing and encoding all run in the browser tab using worker threads. There is no upload step and no API key required.

Tools / Image converter

Bulk image converter

Convert PNG, WebP, AVIF, GIF, BMP and TIFF files to marketplace-ready JPG — or the other way round — with quality, max file size, resize and batch rename controls. Everything runs in your browser, so nothing is uploaded and there is no file limit per day.

Drag and drop images or

JPG, PNG, WebP, AVIF, GIF, BMP, TIFF · up to 1,000 files

Add files to get started. Conversions run on several CPU threads at once, so large batches stay fast and the page stays responsive.

About the bulk image converter

Marketplaces are strict about formats and sizes, and desktop editors make batch conversion slower than it needs to be. This converter re-encodes whole folders to JPG, PNG, WebP or AVIF in your browser, across several CPU threads, without uploading a single file.

The problem it solves

Photo submissions to Adobe Stock and Shutterstock must be JPG, which means anything you finished as PNG, TIFF or WebP needs converting first. Meanwhile the same images are wanted in other formats elsewhere: WebP or AVIF for a portfolio site, PNG when transparency matters, smaller JPGs for client previews. Doing that in an editor means an export dialog per batch and a lot of waiting.

Uploading a few hundred full-resolution files to an online converter is worse: it is slow on domestic upload speeds, and it hands finished, unwatermarked work to a third-party server. Browsers can now decode and encode all four of those formats natively, so the conversion belongs on your own machine.

How it works, step by step

1. Add a batch
Drop files or a folder onto the page. Each file is queued locally with its size and dimensions read up front, so you can see what you are about to process.
2. Choose an output format
JPG for stock submissions, PNG when transparency must survive, WebP for small portfolio previews, AVIF for the smallest files at the same visual quality. Each option lists its trade-off next to it so the choice is not guesswork.
3. Set quality and dimensions
Pick a quality level for lossy formats and, optionally, a maximum long-edge dimension. Aspect ratio is always preserved, and images already smaller than the limit are not upscaled.
4. Convert in parallel
Jobs are spread across several worker threads, so large batches use the CPU you actually have while the page stays responsive. Live counters show completed files, failures, and how many bytes the batch has saved so far.
5. Download
Grab files one at a time as they finish, or take the whole batch as a ZIP once the queue drains. Originals on disk are untouched throughout.

Practical guidance on settings

For stock submission, convert to JPG at a high quality setting and leave dimensions alone — marketplaces have minimum megapixel requirements, and shrinking a file to save space can push it under the floor. Check the batch with the spec checker afterwards if you are unsure.

For a portfolio or blog, WebP or AVIF at a moderate quality with a long edge around 2,000 pixels is usually indistinguishable from the original on screen at a fraction of the weight. Note that re-encoding a lossy file is always generational: convert from your highest-quality master rather than from an already-compressed JPG when you have the choice.

Questions about this tool

Which formats can it read and write?: It writes JPG, PNG, WebP and AVIF, and reads whatever your browser can decode — which covers JPG, PNG, WebP, AVIF and GIF, plus TIFF in some browsers. Camera raw files are not supported; export those from your editor first.
Do converted files keep their metadata?: Re-encoding produces a new file, so embedded metadata is not carried across. Convert first, then run the batch through the metadata embedder to write titles and keywords into the finished files.
Is there a file or batch size limit?: The practical limit is your machine's memory rather than a fixed number, since everything is decoded locally. Very large batches of high-resolution files are best run a few hundred at a time.
Will converting to JPG hurt image quality?: JPG is lossy, so some data is always discarded. At a high quality setting the difference is invisible at normal viewing sizes, but avoid repeatedly converting an already-compressed JPG, because each pass compounds the loss.
Does anything leave my computer?: No. Decoding, resizing and encoding all run in the browser tab using worker threads. There is no upload step and no API key required.