TL;DR

Amazon Q Developer excels at complex, multi-step agentic workflows and is the clear choice if you're heavily invested in AWS, offering built-in security scanning and legacy application modernization tools. GitHub Copilot focuses on streamlined inline code completion with strong VS Code integration and enterprise authentication features, making it better suited for teams prioritizing editor-native autocomplete over broader development tasks. Q Developer claims higher code acceptance rates and provides API access, while Copilot offers multi-model support but no API. Choose Q Developer for AWS-centric projects and complex automation; choose Copilot for simpler, editor-focused pair programming.