SVG — Scalable Vector Graphics — is completely separate from JPG. JPG saves photos as a pixel grid, SVG stores illustrations as mathematical definitions of shapes, lines and colors. Meaning SVG files can be displayed at every size — from a small icon to a large banner — with no quality loss.
Changing JPG to SVG is a operation called vectorization, and it is particularly valuable for illustrations and flat artwork.
Prior to converting JPG to SVG, check here it is essential to understand what the conversion actually does. JPG files are a pixel-based image — a static grid of pixels. SVG files are a mathematical image — a series of geometric shapes which software uses to draw the graphic.
The conversion works great for uncomplicated graphics with defined shapes and limited colors — icons, logos, symbols and illustrations. It does not work for complex photos with thousands of colors.
For best output, Illustrator's Image Trace function gives the most flexibility. Load the image in Illustrator, select the graphic, access the Image Trace panel and pick an appropriate preset.
Try alljpgconverters.com for a totally free browser-based JPG to SVG tool without download required.