Free Bulk Image Converter Online: Batch Convert Images Between Formats

Converting one image is easy; converting fifty of them one at a time is tedious. Bulk conversion solves that: you drop in a whole folder of mixed images, pick one output format, and download the lot. This guide covers when bulk conversion is the right tool, how to do it in your browser, and how to choose the target format so the results are right the first time.

When to use bulk conversion

• A camera roll of HEIC photos that need to be JPG so Windows, older devices, and most websites can open them.
• A set of PNG screenshots you want as smaller JPGs for a report or email.
• Mixed-format assets (PNG, WebP, BMP) that need standardising to one format for a project or upload.
• Web preparation — converting a batch to WebP for a site you control.

How to convert images in bulk

Open Bulk Convert Images, then:

• Add all the images you want to convert — select the whole set at once.
• Choose a single output format (for example JPG, PNG, or WebP) for the entire batch.
• Convert, then download the results, usually packaged as a single ZIP so you are not saving files one by one.

The conversion runs in your browser, so the images are processed on your device and never uploaded to a server — useful when the batch contains personal photos or unreleased work. If you only need to convert a single image, the regular image converter is quicker.

Choosing the output format

The right target depends on what the images are. Choose JPG for photographs that need to be small and universally openable. Choose PNG when the images are graphics, screenshots with text, or need transparency. Choose WebP for images going onto a website you control, where the smaller size helps load speed. Converting photographs to PNG is the most common mistake — it makes the files much larger for no visible benefit.

Common mistakes to avoid

• Converting photos to PNG — use JPG or WebP for photographs to keep files small.
• Expecting transparency to survive a JPG conversion — JPG has no transparency, so transparent areas become a solid background.
• Converting to WebP for files you will email — some mail clients and older apps cannot open WebP; use JPG/PNG for sharing.
• Forgetting to compress afterward — conversion changes format, not necessarily size; compress if the batch is still heavy.

The most common case: HEIC to JPG

By far the most frequent reason people convert a batch is HEIC photos from an iPhone. iOS saves photos as HEIC to save space, but Windows, many older devices, some web forms, and a lot of editing software cannot open them. Converting the whole camera roll to JPG in one pass solves it — add the HEIC files, choose JPG, and download the ZIP. The images keep their quality; only the container format changes to one that opens everywhere.

Organising the output

When you convert dozens of files at once, the download usually arrives as a single ZIP. Unzip it into a clearly named folder so the converted versions do not get mixed up with the originals, and keep the originals until you have confirmed the conversions are correct. If you are converting for a specific destination (a website, a marketplace, a print order), check that destination's format and size rules first so you convert to the right target once rather than twice.

After converting

If the converted files are still larger than you need, run them through Compress Image, or use Resize Image if they also need smaller dimensions. To understand which format suits which image, see our JPG vs PNG vs WebP guide, or browse all image tools.