Timepix4 is a programmable general purpose hybrid pixel detector readout ASIC, with a larger chip area and improved time stamp precision and hit rate capability in comparison to its predecessor, Timepix3. The Timepix4 ASIC consists of a matrix of 448 x 512 pixels with a pixel pitch of 55μm. By utilising Through-Silicon-Via (TSV) technology, the ASIC has been designed to be 4-side buttable, permitting almost seamless tiling on all 4 sides. The detector can be applied to a wide range of applications including X-ray imaging, particle tracking and material analysis.