Convert CRYPT9 to CRYPT6

WhatsApp database backup files, including .crypt9 backups, are encrypted to ensure the privacy and security of user data. Converting a .crypt9 backup file to an older version like .crypt6 is not a straightforward process, and it may not be supported by WhatsApp or its related tools due to security and compatibility reasons.

Here are some important points to consider:

1. Backup Version Compatibility: WhatsApp updates its encryption methods and database formats on a regular basis. Some of the newer backup formats, such as .crypt10, crypt14, etc., may not be compatible with older versions, such as .crypt6. Trying to convert a .crypt9 backup to an older version could result in data loss or corruption.

2. Official WhatsApp Tools: WhatsApp provides built-in mechanisms for creating backups and restoring chat history. These backups are usually encrypted with the latest encryption methods. It's recommended to use the official WhatsApp backup and restore features rather than attempting to convert backups to older formats.

3. Security Concerns: Decrypting or converting WhatsApp backup files may raise security concerns and could potentially violate WhatsApp's terms of service or applicable laws. WhatsApp's end-to-end encryption is designed to protect user data, and tampering with backups may compromise that security.

In order to transfer chat history between devices or to recover deleted messages, you should consider the following steps:

• WhatsApp Backup and Restore: Use WhatsApp's built-in backup and restore functionality to transfer your chat history between devices or restore deleted messages. WhatsApp typically stores backups in the cloud or on your device.

• Third-Party Tools: There are third-party tools and software available that claim to convert WhatsApp backup formats. Be cautious when using such tools, as they may not be secure or reliable.

• Contact WhatsApp Support: If you encounter issues with your WhatsApp backups, you can contact WhatsApp support for assistance.

Keep in mind that user privacy and data security are of utmost importance, and manipulating WhatsApp backup files may have unintended consequences. You should always comply with WhatsApp's terms of service and privacy policies when dealing with WhatsApp backups and data.

Simply put, it is impossible to convert CRYPT9 to CRYPT6 directly.
Thus, there is no so-called crypt9 to crypt6 converter or a free online .crypt9 to .crypt6 converter to be found.