Upgrading From a Previous Version

Please read the upgrade notes corresponding to the version you are upgrading from.

See also Backward Compatibility Notes.

Note

If you don’t know what version of CodeIgniter you are currently running, you can get it from the Debug Toolbar, or simply echo the constant \CodeIgniter\CodeIgniter::CI_VERSION.

• Backward Compatibility Notes
• Upgrading from 4.5.5 to 4.5.6
• Upgrading from 4.5.4 to 4.5.5
• Upgrading from 4.5.3 to 4.5.4
• Upgrading from 4.5.2 to 4.5.3
• Upgrading from 4.5.1 to 4.5.2
• Upgrading from 4.5.0 to 4.5.1
• Upgrading from 4.4.8 to 4.5.0
• Upgrading from 4.4.7 to 4.4.8
• Upgrading from 4.4.6 to 4.4.7
• Upgrading from 4.4.5 to 4.4.6
• Upgrading from 4.4.4 to 4.4.5
• Upgrading from 4.4.3 to 4.4.4
• Upgrading from 4.4.2 to 4.4.3
• Upgrading from 4.4.1 to 4.4.2
• Upgrading from 4.4.0 to 4.4.1
• Upgrading from 4.3.8 to 4.4.0
• Upgrading from 4.3.7 to 4.3.8
• Upgrading from 4.3.6 to 4.3.7
• Upgrading from 4.3.5 to 4.3.6
• Upgrading from 4.3.4 to 4.3.5
• Upgrading from 4.3.3 to 4.3.4
• Upgrading from 4.3.2 to 4.3.3
• Upgrading from 4.3.1 to 4.3.2
• Upgrading from 4.3.0 to 4.3.1
• Upgrading from 4.2.12 to 4.3.0
• Upgrading from 4.2.11 to 4.2.12
• Upgrading from 4.2.10 to 4.2.11
• Upgrading from 4.2.9 to 4.2.10
• Upgrading from 4.2.7 to 4.2.8
• Upgrading from 4.2.6 to 4.2.7
• Upgrading from 4.2.5 to 4.2.6
• Upgrading from 4.2.3 to 4.2.5
• Upgrading from 4.2.2 to 4.2.3
• Upgrading from 4.2.1 to 4.2.2
• Upgrading from 4.2.0 to 4.2.1
• Upgrading from 4.1.9 to 4.2.0
• Upgrading from 4.1.7 to 4.1.8
• Upgrading from 4.1.6 to 4.1.7
• Upgrading from 4.1.5 to 4.1.6
• Upgrading from 4.1.4 to 4.1.5
• Upgrading from 4.1.3 to 4.1.4
• Upgrading from 4.1.2 to 4.1.3
• Upgrading from 4.1.1 to 4.1.2
• Upgrading from 4.0.5 to 4.1.0 or 4.1.1
• Upgrading from 4.0.4 to 4.0.5
• Upgrading from 4.0.x to 4.0.4
• Upgrading from 3.x to 4.x
  • Upgrade Models
  • Upgrade Views
  • Upgrade Controllers
  • Upgrade Configuration
  • Upgrade Database
  • Upgrade Emails
  • Upgrade Encryption
  • Upgrade Working with Uploaded Files
  • Upgrade HTML Tables
  • Upgrade Image Manipulation Class
  • Upgrade Localization
  • Upgrade Migrations
  • Upgrade Output Class
  • Upgrade Pagination
  • Upgrade Routing
  • Upgrade Security
  • Upgrade Sessions
  • Upgrade Validations
  • Upgrade View Parser