jamiechong

Export 2 Multisite exports your standalone database SQL for import into a WP multisite installation. It handles duplicate users (based on email) and will copy over all site settings including Widgets and Menus. You still need to copy the files for your themes, plugins and uploads.
<ul>
<li>This plugin has been minimally tested, but has been used to successfully migrate a handful of standalone sites to a multisite installation.</li>
<li>There is a good possibility it won’t work for sites that make use of a multitude of plugins – especially plugins that have their own database tables.</li>
</ul>
Installation
<ol>
<li>Create a new site on the Multisite.</li>
<li>Copy the plugins and themes from this standalone site to the Multisite.</li>
<li>Copy the files from wp-content/uploads/ on this site to wp-content/uploads/sites// on the multisite.</li>
<li>Backup the database on the Multisite.</li>
<li>Provide the Site ID of the Multisite. This can be found by hovering the mouse over the new site on Network Admin->Sites.</li>
<li>Provide the New URL. Example: //mysite.my-wp-multisite.com</li>
<li>Provide the New file path (The file path of the Multisite installation).</li>
<li>Export the database dump.</li>
<li>Import the SQL into your Multisite installation.</li>
</ol>
<ul>
<li>Important: The exported SQL will DROP the tables that were created for the Site ID you provided. So only perform this migration on new empty Sites.</li>
<li>Note that the you may need to review the exported SQL to ensure that plugin database tables have been exported correctly.</li>
<li>The site admin (username and password) is the user you created while creating the new Site, NOT the site admin of this standalone site.</li>
<li>The guts of this export plugin were inspired by <a href="https://iandunn.name/comprehensive-wordpress-multisite-migrations/" rel="nofollow ugc">this blog post</a></li>
<li>The code for this plugin has been modified from the <a href="https://wordpress.org/plugins/wp-migrate-db" rel="ugc">WP Migrate DB</a> plugin, but should not conflict with it in any way.</li>
</ul>

Export 2 Multisite

Exports your standalone database SQL for import into a WP Multisite installation.

Frank Bueltge

Inpsyde GmbH

Simon Kraft

WP Media

ChriCo

Rene Reimann

s-hinse

With Search & Replace you can search for everything and replace this with everything but before you do this you can easily create a simple database backup and restore it.
For avoiding problem please keep in mind that this plugin search and replace strictly what is specified in “Replace With”. 
Common error example: 
Search For: http://web.com/wordpress/ 
Replace With: http://neuweb.com/wordpress 
The url become something like: http://neuweb.com/wordpresscontent/…
Correct “Replace with”: 
Search For: http://web.com/wordpress/ 
Replace With: http://neuweb.com/wordpress/ 
The url become something like: http://neuweb.com/wordpress/content/…
We have implemented special features!
The first one is “Replace a Domain / URL” that is useful for a quick and simple transfer or a migration of a WordPress site. 
The second feature is full support for serialized data. There are a lot more features – check them out! 🙂
Our goal with this plugin is to give you a good solution for manipulating your data for both Developers and Users of WordPress.
<blockquote>
Note: This plugin requires PHP 5.6 or higher to be activated.
</blockquote>
<a href="https://github.com/wp-media/search-and-replace" rel="nofollow ugc">Checkout our GitHub Repository</a>
<h4>Features</h4>
<ul>
<li>Search & replace data in your WordPress database</li>
<li>Change domain/URL of WordPress installation</li>
<li>Handle serialized data</li>
<li>Choose dry run or download SQL file</li>
<li>Change table prefix</li>
<li>Backup & restore your database</li>
<li>WordPress Multisite support</li>
<li>Localized and ready for your own language</li>
</ul>
<h4>Crafted by WP Media</h4>
Made by <a href="https://wp-media.me" rel="nofollow ugc">WP Media</a>.
<h4>Donation?</h4>
You want to donate – we prefer a <a href="https://wordpress.org/support/view/plugin-reviews/search-and-replace?rate=5#postform" rel="ugc">positive review</a>, not more.

Search & Replace

Search & Replace data in your database with WordPress admin, replace domains/URLs of your WordPress installation.

Export 2 Multisite vs Search & Replace