How to batch convert a whole folder of images

10 September 2026 · 5 min read

Here is a shape of problem that comes up constantly after a shoot: you have 50 folders, five photos in each, one folder per product. What you need is 250 web-ready JPGs, all the same size, all in one place, named sensibly.

Doing that one image at a time is an afternoon. Here's how to do it in a couple of minutes, and what the realistic options are.

What "batch" actually needs to cover

Most tools handle the easy half — converting many files that are already sitting in one folder. The parts that actually cost you time are:

Nested folders — pulling images out of dozens of subfolders into one flat set.
Uniform resizing — every image to the same long edge, without upscaling the small ones.
Name collisions — when every folder contains a 1.jpg.
One tidy output — a single folder at the end, not 250 separate downloads.

The options

Photoshop actions / Image Processor

Powerful and precise, and the right answer if you already live in Photoshop. File → Scripts → Image Processor will run a folder and can include subfolders. The downsides: it's slow to start, it's a paid app, and setting up an action for a one-off job is often more work than the job.

Mac Preview / Automator

Free and built in. Select images in Preview and use Tools → Adjust Size to resize in bulk; Automator can build a reusable "Convert and resize" quick action. It's fiddly to set up, and it won't flatten nested folders for you.

ImageMagick (command line)

The most capable option if you're comfortable in a terminal. Something like:

magick mogrify -path ./out -resize 2000x2000 -quality 82 -format jpg ./**/*.jpg

Fast and scriptable, but it's an install, a syntax to learn, and easy to overwrite originals with one wrong flag.

Browser-based

No install, nothing to learn, and — for a tool that processes locally — your files never leave the machine. This is what the Jump Studio converter does.

Doing it in the browser

Open the image converter.
Select all your folders in Finder or Explorer and drag them onto the drop zone together. Every image inside gets pulled out — at any nesting depth — into one queue.
Pick your output format. JPG for photos, WebP if it's going straight onto a website.
Set resize to a long edge — 2000px is a sensible ecommerce default — and leave don't enlarge on so smaller files aren't upscaled.
Optionally set a target file size so nothing exceeds your limit.
Turn on rename if you want clean sequential names.
Turn on bundle as zip — you get one file that unzips to one folder.
Export.

On the folder picker: the "choose folder" button can only ever select one folder — that's an operating-system limit, not the tool. To do many folders at once, drag them in. Or put them all inside one parent folder and pick that; subfolders are included.

Batch convert a folder

Drag in as many folders as you like. Resize, compress and rename in one pass.

Open the image converter →

The name-collision trap

This is the one that quietly ruins batch jobs. If each of your 50 folders contains a 1.jpg, flattening them into one folder means 50 files competing for the same name — and a naive tool will overwrite until you're left with one.

Two ways to avoid it:

Rename with a sequence. Turn renaming on and every file gets a unique numbered name — product-001.jpg through product-250.jpg.
Let the tool de-duplicate. Jump Studio automatically suffixes repeats (1.jpg, 1-2.jpg, 1-3.jpg) so nothing is silently lost even with renaming off.

Worth knowing either way: if you flatten folders, check your output count matches your input count.

Sensible batch settings

Job	Format	Long edge	Target size
Ecommerce product shots	JPG	2000px	300KB
Website / blog imagery	WebP	1600px	200KB
Client contact sheet	JPG	1200px	150KB
Social media	JPG	1080px	200KB
Email-able previews	JPG	1000px	100KB

Common questions

How many images can I convert at once?

A few hundred is comfortable. Everything is processed on your own machine, so the real limit is your computer's memory rather than an upload cap or a per-file allowance.

Will it change my original files?

No. Converting produces new files; the originals are read and left untouched. That's a genuine advantage over command-line tools, where one wrong flag can overwrite a folder in place.

Can I resize without changing the format?

Yes — set the output format to the same one your files already are, and just apply the resize. Note that JPGs are re-encoded when saved, so use a high quality setting (or a generous target size) if you're keeping them as masters.

Can I crop everything to the same aspect ratio?

Yes. Bulk crop applies a centred crop at a chosen ratio — 1:1 for square product grids, for example — across the whole queue in the same pass as the resize.