It traces registers, recognizes procedures, API calls, switches, tables, constants and strings, as well as locates routines from object files and libraries.

[4] The software is free of cost, but the shareware license of version 1.x requires users to register with the author.

[7] The disassembler part of OllyDbg is free software, released under the GNU General Public License.

For cracking and reverse engineering, it is often the primary tool because of its ease of use and availability; any 32-bit executable can be used by the debugger and edited in bitcode/assembly in realtime.

[10] It is also useful for programmers to ensure that their program is running as intended, and for malware analysis purposes.