How to make a photo mosaic picture online for free!

Big picture is the picture mosaic looks like from a distance. It should be a simple image. Rule of thumb is that it will make a good "big picture" if you can make out what it is as a small thumbnail. Crop it into one of many common frame sizes. Mosaic has same width to height ratio as the big picture.

Small pictures are pictures that make up the mosaic. Tiles are square, so if default center crop doesn't look good, move the crop area, and crop it. You don't need to crop it if the default center crop looks good. Use many photos with various different colors that match the colors of the big picture.