At what height over the earth does the ozone layer exist?

The ozone layer exists at 25 km height over the earth.
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation.
The ozone layer is mainly found in the lower portion of the stratosphere, from approximately 15 to 35 kilometers above Earth, although its thickness varies seasonally and geographically.