The present disclosure relates to a leak-resistant slider zipper. The zipper typically includes end seals at the opening and closing ends of the zipper, an upper and a lower set of interlocking elements, first and second upper flanges above the upper interlocking elements having no gaps or cut-outs therein, and first and second lower flanges below the lower interlocking elements, one of the lower flanges being folded back on itself, and a slider.