This plugin allows you to select your “From”, and “To” Taxonomies, to convert all terms. Optionally select a parent term to limit terms to switch. Typing term names will do a live search of terms with the name you are typing AND possess child terms.
Plugin also has built-in support for WP-CLI. In the command line, type in wp taxonomy-switcher for instructions.
Plugin is on GitHub. Pull Requests and Forks welcome.
Notes
Please keep in mind, if parent isn’t set, or you don’t specify a comma-separated list of term ids to migrate, it will migrate all terms for that taxonomy to the new taxonomy.
Pluginize was launched in 2016 by WebDevStudios to promote, support, and house all of their WordPress products. Pluginize is not only creating new products for WordPress all the time, but also provides ongoing support and development for WordPress community favorites like CPTUI, CMB2, and more.