Vector Magic - Easily convert JPG, PNG, BMP, GIF bitmap images to SVG, EPS, PDF, AI, DXF vector images with real full-color tracing, online or using the desktop app!
potrace - Open source program that transforms bitmaps into vector graphics.
SVGConverter - Free Online SVG converter software that converts your PNG, JPG/JPEG, BMP, TIFF, WEBP, PDF to SVG, AI, EPS, PDF.
Vectorizer.io - Fast and easy way to vectorize an image online
Autotracer.org - Free online image vectorizer
Super Vectorizer - Mac vector trace tool to convert raster png to SVG vector graphic.