Image Combiner for Thumbnails

What this image combiner does

This image combiner puts two, three or four pictures into one file: side by side, top and bottom, three across or in a 2×2 grid. By default the result is 1280×720, the size YouTube recommends for a custom thumbnail, so a before-and-after, a versus shot or a product comparison comes out ready to upload. Shorts-shaped 1080×1920 and square 1080×1080 outputs are there too, along with an original-sizes mode that crops nothing.

How to put two pictures side by side

1. Add the images. Drop two files onto the page, paste them, or pick them from your disk. With two images the panels are labelled BEFORE and AFTER to start with; change or clear the labels as you like.
2. Pick a layout and size. Side by side is the default. Top and bottom suits a vertical Shorts cover, where two wide halves read better than two thin ones.
3. Set the focus of each image. Each photo is cropped to fill its panel. The two focus sliders move the crop window, so a face near the edge of the frame can be kept in shot instead of being cut off.
4. Adjust the divider and download. Set the line width and colour, choose JPG, PNG or WebP, and save. The file size is shown after every download.

Why the crop matters more than the merge

Most free tools that rank for combining images do one of two things: stretch every picture to the same height and paste the strips together, which gives you an output of whatever odd size the inputs add up to, or hand you a collage template that needs an account before it will export. Neither helps when the destination is a fixed 16:9 frame. Here the output size comes first and each image is fitted to its panel, with you deciding what stays. Nothing is uploaded, nothing is watermarked, and there is no export limit.

When you do want the files joined without any cropping, choose Original sizes. Every image is scaled to a shared height, or width when stacked, and placed end to end.

Making the comparison readable

A split thumbnail is seen at a fraction of its real size, so each half needs one clear subject and the difference between them has to be obvious at a glance. Keep framing and lighting the same across both shots where you can, and use short labels. Check the finished file with the thumbnail preview, add a headline with add text to thumbnail, and see how split layouts are used in fitness thumbnails and reaction thumbnails. If you would rather not assemble it by hand, generate a thumbnail instead.

Last updated October 25, 2026.