jquery-4 - jQuery 4.0 Migration Guide
Migrate jQuery 3.x to 4.0.0 safely in WordPress and legacy web projects
Tags
Updated: 2026-02-09Capabilities
Typical Inputs
Typical Outputs
What this skill does
- identify jQuery 4.0 compatibility issues
- add jquery-migrate plugin for testing
- replace removed utility functions
- handle focus event order changes
- migrate slim build dependencies
- update WordPress jQuery integration
- implement polyfills for compatibility
- apply ES modules import syntax
- enable Trusted Types support
- check for breaking changes
Inputs
- jQuery 3.x codebase
- WordPress project
- legacy JavaScript code
- jQuery migrate plugin
- console warnings
- breaking changes reference
- native JavaScript equivalents
- focus/blur event handlers
- AJAX script loading
- ES modules configuration
- Trusted Types policy
Outputs
- jQuery 4.0 compatible code
- console warning reports
- updated utility function calls
- migrated WordPress integration
- fixed focus event order
- updated slim build usage
- ES module import statements
- Trusted Types compliant code
- polyfill implementations
- migration documentation
Requirements
- jQuery 4.0.0 or later
- jquery-migrate 4.0.2 or later
- modern browser environment
- WordPress installation
- JavaScript runtime
- console access