Since the nowadays used lead-based primary explosives, lead azide, picrate and styphnate suffer from various environmental and toxic issues, there is a great need for new green materials. Therefore, two highly promising lead-free primary explosives potassium 1-(N-nitramino)-5H-tetrazolate (1, 1-KNAT) and potassium 2-(N-nitramino)-5H-tetrazolate (2, 2-KNAT) have been synthesized and characterized. Both isomers show superior energetic performance, initiation capability and were comprehensively analyzed by low-temperature X-ray diffraction, IR, multinuclear NMR spectroscopy, elemental analysis, and DTA. Sensitivity determinations toward impact, friction, and electrostatic discharge revealed its highly powerful, but also sensitive character. In addition, their potential as lead-free primaries were evaluated in initiation tests of PETN or RDX filled detonators confirming their great suitability as lead-free primary explosives.