JA K2 to com content migration plugin is a Joomla plugin to migrate K2 content to Joomla comcontent in one go. It can convert all K2 elements: K2 categories, K2 Items, K2 Extra fields group, K2 extra fields, K2 tags. For K2 extra field, you can rename it if necessary.
JoomlArt
2022-12-21
re you looking for the tool to export users (download users) into Excel or CSV file?
Quick unit converter that converts common units of measurement.
Acceleration , Area , Torque , Electricity , Energy , Force , Force / Length , Length , Light , Mass , Mass Flow , Density , Mass capacity , Power , Pressure & Stress , Temperature , Time , Velocity & Speed , Viscosity , Volume & Capacity , Volume Flow
CMigrator2.2.0 
So, you’ve made the mistake of choosing the wrong CMS(Wordpress or Drupal :)) in the past? Well, don’t worry, now you have the option to switch to Joomla with ease. With CMigrator you can import your categories, posts, pages and users from Wordpress or Drupal directly into Joomla/K2 with just few clicks.
JMigrator Virtuemart addon
Requirements
JMigrator
Virtuemart
JConverter1.8 
UPDATE (Oct, 2014): JConverter 1.5 supports import of images from Wordpress to Joomla. It also supports importing same URL alias from Wordpress in Joomla so you can keep same URL in new site with minimal changes.
This plugin migrates sections, categories, posts, images, medias and tags from Joomla to WordPress.
It has been tested with Joomla versions 1.5 through 3.9 and WordPress 5.2 on huge databases (72 000+ posts). It is compatible with multisite installations.
SP Transfer 6.3 
Use this tool to transfer files or database items between two different Joomla! sites, or duplicate items within your live site. This is a 'mass' copy/paste tool necessary for ALL Joomla! administrators.
JMigrator for joomla5.3.4 
If you are still running an old version of Joomla your website is at risk. Old enough that Joomla development team is not supporting these versions anymore.
jUpgradePRO3.8 