Batch File Conversion: How to Convert Multiple Files at Once

Converting files one at a time is fine for a single receipt or a quick screenshot. But when you have 50 product photos to turn into a PDF catalogue, or 30 scanned pages to combine into one document, you need a batch workflow.

What is batch conversion?

Batch conversion means processing multiple files through the same operation in a single pass — instead of uploading, converting, and downloading one file at a time.

Batch workflows with free online tools

Combine multiple images into one PDF

The most common batch operation. Use Image to PDF to:

1. Select all your images at once (Ctrl+A in the file picker, or drag a folder).
2. Reorder them by dragging thumbnails.
3. Download a single PDF with one page per image.

This works with JPG, PNG, WebP, GIF, and BMP — you can even mix formats in one upload.

Merge multiple PDFs into one

Have five separate PDF files that should be one document? Merge PDF lets you:

1. Upload all PDFs at once.
2. Drag to reorder.
3. Download the combined file.

Compress multiple images

Before combining images into a PDF, batch-compress them to keep the final file size manageable:

1. Run each image through Compress Image.
2. Then combine the compressed versions using Image to PDF.

Tips for efficient batch workflows

1. Name files with numbers

Name your files 01-cover.jpg, 02-intro.jpg, 03-chapter1.jpg. Most upload tools sort alphabetically, so numbered prefixes keep pages in order.

2. Use consistent file formats

Mixing JPG and PNG in one batch is supported, but sticking to one format avoids unexpected differences in quality or transparency handling.

3. Compress before combining

A 50-image PDF where each photo is 5 MB produces a 250 MB document. Compress each image to under 500 KB first, and the final PDF will be a fraction of that size.

4. Check the output

After a batch conversion, open the result and scroll through every page. Catching a missing or out-of-order page now is much easier than redoing the entire batch later.

5. Know the file size limits

Free accounts support up to 10 MB per file. If your batch includes large files, either compress them first or upgrade to Premium for 100 MB per file.

Common batch use cases

Frequently asked questions

Is there a limit on the number of files?

There is no hard limit on the number of files in a batch. The constraint is the total upload size — 10 MB for free users, 100 MB for Premium.

Can I batch convert PDFs to images?

PDF to JPG extracts all pages from a PDF as separate images in one pass — effectively a batch operation in reverse.

Do batch operations take longer?

Processing time scales with the number and size of files, but the total time is significantly less than converting each file individually.

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Try it now: Image to PDF, Merge PDF, Compress Image, or browse all converters.