This protocol describes the fragmentation of HMW DNA from one of the MagAttract v.2, Plant MagAttract v.3, or Plant MagAttract v.4 Sanger Tree of Life HMW DNA extraction protocols, using the Diagenode Megaruptor®3. This process is highly effective for the clean-up and shorter fragment removal from DNA extracts from all of the taxonomic groups covered by the Tree of Life Programme, with DNA sheared into an average fragment size range of 12–20 kb. However, highly concentrated or viscous samples are challenging. The output of this protocol is sheared DNA which can be directed towards Fragmented DNA clean up, with either the Manual or Automated SPRI protocols. This protocol was adapted from Sanger Tree of Life HMW DNA Fragmentation: Diagenode Megaruptor®3 for PacBio HiFi in order to process samples resulting from the Sanger Tree of Life HMW DNA Extraction: Automated MagAttract v.2, Automated Plant MagAttract v.3 and Automated Plant MagAttract v.4 protocols. Acronyms HMW: high molecular weight SPRI: solid-phase reversible immobilisation LI: low-input HiFi: high fidelity