Hex Editor / Reverse Engineering
HxD is a free hex and disk editor for Windows developed by Maël Hörz (mh-nexus). It opens files of virtually any size, plus raw disks and system RAM, and presents byte-level views with fast search, replace, export, and file comparison. In ECU tuning it is a staple for inspecting raw firmware reads, locating map or code regions by byte pattern, comparing an original dump against a modified one to confirm exactly which bytes changed, and applying manual patches. Built-in checksum and hash calculators, a data inspector, and fill/insert operations help verify edits and understand binary layout. Tuners reach for it alongside dedicated map editors whenever a change must be checked or performed by hand. It is lightweight, portable, and widely trusted in the community.
Softechpro automates the byte-level edits tuners often make by hand in HxD, applying DPF/EGR/AdBlue/DTC-off modules and correcting checksums across ~1,400 firmwares. You can still open the same file in HxD afterward to verify exactly which bytes changed.
See Softechpro plansTry the file service