Bulk Image Border

How to add a border to images in bulk

1. Add your images. Drop up to 200 JPG, PNG, WebP, BMP, GIF or AVIF files onto the box above, or choose them from your computer. They stay on your machine.
2. Choose a border. Either a fixed amount on each side, or pad every image out to one shape. Each row shows the size it will come out at before you run anything.
3. Add and download. Take the images one at a time, or download the whole batch as a ZIP.

Padding to a square, without cropping

Marketplaces and product grids usually want a square, and photographs usually are not one. The blunt fix is to crop, which throws away the sides of every image. Padding does the opposite: it keeps every pixel and adds background to whichever side is short. A 1200×800 photo padded to 1:1 becomes 1200×1200, with 200 pixels of background above and below, and nothing lost.

That fills a real gap between the other tools here. The bulk image resizer in contain mode gives you an image that fits inside a box but is usually smaller than it on one side, and in cover mode it crops. The bulk image cropper only ever removes. If you want every file at exactly one shape with the whole picture intact, padding is the operation that does it.

Why percentages, not just pixels

A 40-pixel border is a hairline around a 6000-pixel photograph and a heavy frame around a 300-pixel thumbnail. Since a batch is rarely all one size, a fixed pixel border is wrong for most of it — so the default here is a percentage, and it is measured against each image's shorter side. That last detail is what makes an even border look even: measuring each side against its own axis would put a thicker band on the top and bottom of a landscape photo than on its sides. Pixels are still there when you need an exact number, and both modes let you set each side separately.

Colour and transparency

The padding can be any colour, or transparent for PNG and WebP, which have an alpha channel to hold it. JPEG does not. Rather than hand back JPEGs with black edges — which is what an unfilled canvas actually encodes — the tool fills a JPEG with the colour you picked and says so before it runs. Every image comes out in the format it went in as, so a transparent PNG keeps its transparency through the operation and a JPEG stays a JPEG. If you want a different format afterwards, the bulk image converter does that on its own.

Limits, and why they exist

This is the one tool here that makes images bigger, which means it is the one that can ask your browser for more memory than it has. A single result is capped at 40 megapixels and 12,000 pixels on a side — enough for a 24-megapixel camera photo padded out to a square. A file that would exceed it fails on its own, with a message naming the size it would have been, and the rest of the batch carries on. The same is true of a file that turns out to be corrupt: one bad image never costs you the other 199.

Why add borders in the browser?

Putting space around a picture is arithmetic on pixels your computer already has. Sending a file to a server to have that done, then sending it back, is slower for a large batch, costs someone money per image, and puts your files on a machine you do not control. Doing it locally is the reason this tool has no sign-up and no usage limit.

Frequently asked questions

Are my images uploaded anywhere?

No. The border is drawn in your browser using the canvas API. Your images never leave your computer, which is why the tool needs no account and has no usage limit.

How do I make every image square without cropping?

Choose "Pad to ratio" and pick 1:1. Each image keeps every pixel it had and gets background added to whichever side is short, so a 1200x800 photo becomes 1200x1200 rather than losing 400 pixels off the sides. That is the difference between this tool and a cropper: one adds space, the other removes picture.

Why is the border a percentage instead of pixels?

Because one batch is rarely one size. A 40-pixel border is a hairline on a 6000-pixel photo and a thick frame on a 300-pixel thumbnail, so a fixed pixel border is wrong for most of a mixed batch. A percentage gives every image the same visual weight. Pixels are there too when you need an exact number.

What is the percentage measured against?

The shorter side of each image. That is what makes an even border look even: measuring each side against its own axis would put a thicker band on the top and bottom of a landscape photo than on its sides.

Can the border be transparent?

Yes, for PNG and WebP, which have an alpha channel. JPEG does not, so a JPEG always gets a solid colour instead — the tool warns you before it runs rather than handing back files with black edges.

How many images can I do at once?

Up to 200 per batch. They are processed a couple at a time rather than all at once, because adding a border makes each image bigger and a browser tab has a memory budget. A file that turns out to be corrupt, or that would come out too large to build, fails on its own and the rest of the batch carries on.