Database Search and Replace Script in PHP

Search Replace DB version 3.1.0 is a user-friendly, front-end tool for developers, that allows you to carry out database wide search/replace actions, that don't damage PHP serialized strings or objects.


It has come to our attention that some users have been leaving this script on their servers despite advice to the contrary. Due to the very real dangers it can present when used that way, we now ask that you complete a form where we make sure you’re aware of these risks in order to receive the download link. Do also carefully read the installation instructions below.

Please check your spam folder for the download link before you email us for support. If you are still experiencing problems, email us politely with your query.


Download the script from the link you received by email, and install it to a secret folder with an obfuscated name. Your server should also not be set to provide directory lists.

A typical WP install with this script would have the folders as follows:


Do not install Search Replace DB to the root folder or in WP’s own folder hierarchy or you risk all sorts of potential problems. Just don’t. It must run in its own folder.

To see how you can use this tool to aid migrations, check out our article on WordPress migrations or visit the WP Tuts+ article that mentions this script.

If you are in any doubt whatsoever about how to use this standalone script, then please consider getting an expert in. It’s a really powerful bit of code that if used badly can damage a WP install beyond repair. If you want help, get in somebody like us, for example, or any of the other great guys listed over at CodePoet.


The code is supplied under the GPL V3 and is fully open source. Do be aware that this means people can change this code and offer it up, and that other versions may be worse… or better. It is code for developers, by developers, and you should only use code from sources you trust.


Please beware of adverts below that offer a download button, but adverts do allow us to partly cover the cost of running this project.


Where do I install the unzipped files?

In a directory on your webserver. It can be an httpauth protected folder if it’s a public facing webserver.

I heard this script is insecure. Is it really?

Yes – it’s a development tool, not something you should be putting on production servers. If you do put it on a production server be really careful. We’re trying to work out ways of protecting users further, because it turns out that this tool is being recommend by webhosts around the world, but too often to quite naive users who don’t really understand the risks.

I get an error 2: Class __PHP_Incomplete_Class has no unserializer

This is a common error and generally comes up with users of Yoast plugins, but also some others. It’s something we’re aware of. In the vast majority of cases everything is fine. You could try running the script from a different PHP install – there is no reason why you can’t have a pipe to a production database and connect to it from your workstation, for example. A little more detail is on our github repository.


Test 20160504

  • Version 3.1.0 (Web UI and CLI versions) tested against PHP 7.0.6 and functioned correctly.
  • Version 2.1.0 confirmed to not work with PHP 7.0.6 but is kept for use on older servers.

Version 3.1.0:

  • Safety checks to prevent deletion when installed incorrectly. However, you should still take care when dealing with files on your server.
  • JavaScript popup confirmation on ‘Delete Me’.
  • Port number option in both the GUI and CLI. Use –port nnn to set a non-default MySQL port.
  • Fixed Drupal bootstrap behaviour. Start up of script uses Drupal data as guide, no longer relies on a full successful Drupal initialisation before script will allow you to proceed.
  • Driver selection improved so that PDO will be attempted first if PDO+mysql is available, with mysqli being used as a fallback. This fixes ‘driver not found’ errors
  • Removed mysql_ functions and replaced with mysqli_.
  • Improved JS preview overlay for dry runs. This means that the right pane will always show the most accurate data possible. If serialised strings are present, highlights are not displayed.

Version 3.0.0:

  • Major overhaul
  • Multibyte string replacements
  • UI completely redesigned
  • Removed all links from script until ‘delete’ has been clicked to avoid security risk from our access logs
  • Search replace functionality moved to it’s own separate class
  • Replacements done table by table to avoid timeouts
  • Convert tables to InnoDB
  • Convert tables to utf8_unicode_ci
  • Use PDO if available
  • Preview/view changes
  • Optionally use preg_replace()
  • Scripts bootstraps WordPress/Drupal to avoid issues with unknown serialised objects/classes
  • Added marketing stuff to deleted screen (sorry but we’re running a business!)

Version 2.2.0 (never formally released but patched into v3.0.0):

For changes prior to v2.2.0 please refer to index.php where you will find a complete changelog. You can also browse the project on github.

To Be Done

  • Ensure UTF8 encoding is enforced (see comments). Added in v2.1.0
  • Self deletion or security system to prevent accidental security risks. Added in v3.0.0
  • Release CLI version for use on non-WP sites, or for other purposes (already supports use on any MySQL DB.) Added in v3.0.0
  • Change to GPL V3. Added in v3.0.0
  • Eliminate warnings and remove deprecated function calls. Added in v2.1.0
  • Add facility to subscribe to interconnect/it Newsletter. Added in v3.0.0
  • Confirm deletion has actually happened.
  • Add old versions for download to this page.


We’d love to get contributions, bug reports and more on the Search Replace DB github repository. Please come on over – you’ll be more than welcome but you will need to request access by emailing


We’ve been asked a lot in the comments box below about accepting donations. But you can’t believe what a headache that is from an accounting and tax perspective.

Consequently all we can say is that if you wish to you can buy a personal gift for the key developers from one of the wishlists below – especially given that it’s a spare time project. If others who have contributed wish to provide us their wishlist links then we’d be more than happy to add them.

1,562 responses to “Database Search and Replace Script in PHP

  1. I like this one and use it very often.

  2. Thanks!!!! 🙂

  3. This is the best way to change files routes when you move your wp site, thank you very much!

  4. thanks alot for this script.
    Helped me change all my domain url easily. Had been pulling my hairs to do this task but this tool made it so simple
    thanks again and you are awesome bro

  5. This work for me! thank you.

  6. I’ve been using your script for many years but I never thought of dropping a line to let you know you are awesome. So here you go:


    Grazie mille!

  7. GREAT TOOL! I tried to use the 3.1 version in an Azure environment and it shows an AJAX error, I tried with the 3.0 and worked perfectly. Any idea?

    1. Occasionally people do experience AJAX errors – we suspect mostly it’s a time out but sometimes there are messages in the system log hinting at this.

      What happens if you do one table at a time?

  8. Awesome script!
    I had to move a wordpress installation with domain-change. The script did exactly what to do and everything works after the search-and-replace.

    Thank’s a lot.

  9. The script is not working for me. My aim is to replace the old domain name to new domain. After i filled the necessary and i hit live button and it runs without changing anything. Any help give me necessary step to follow?

    1. No one to help me here?

    2. There are a great many reasons why it might not work – security, connection, server config and so on.

      You can get a developer to help you look into this if you need it, but they’ll usually charge. It should just work by following the on-screen instructions. You could always try an older version of the script.

    3. It’s quite tricky – you don’t give a lot of information. For example, which version are you running, what does the dry run look like, and what are the strings you’re using?

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