bitmap image to vector, convert your pixel art bitmap online to a vector file, trace bitmap, raster to vector, pixel to illustrator, pixel to svg :: drububu's pixel art tutorial
If you want to use your images as vector graphic you need to convert your bitmap image into a resolution independent vector graphic. This process is referred to with several names, such as trace bitmap, raster to vector, vectorize image, pixel to illustrator, bitmap to vector, etc..