Audacity 4.0 Qt Rewrite: Open-Source Audio Editor Rebuilt

Audacity 4.0 is here, and it's not just a point release. The open-source audio editor has been rebuilt from the ground up on Qt, introducing a new clip-editing model, workspace system, and native high-DPI rendering — the biggest architectural change in the project's 25-year history.

What shipped

The headline feature is the migration from wxWidgets to Qt, unlocking native high-DPI rendering, dockable panels, and a modern UI framework. Clips now have headers you can click to select directly; multi-clip selection, grouping, and simultaneous editing (move, trim, time-stretch) work without workarounds. The separate Select, Envelope, Draw, and Multi-tool modes are gone — their functions are context-sensitive now, accessed via keyboard shortcuts like holding S to split.

Workspaces are new: save and switch between Modern, Classic, and Music layouts. Light, dark, and high-contrast themes ship out of the box with accent colors and track color customization. The project format bumps to .aup4 (with automatic conversion from .aup3), and official Windows builds now include native ASIO support.

Why it matters

Audacity has been the default open-source audio editor for decades — podcasts, radio, education, indie music production. But its wxWidgets interface had aged poorly on high-DPI displays, and the clip model was showing its 2000s-era assumptions. This rewrite modernizes the editor without breaking core workflows, and the Qt foundation opens the door for future improvements like proper plugin hosting and GPU-accelerated rendering.

The release also signals something broader: mature open-source projects can execute major architectural rewrites. At 1035+ points on Hacker News in its first day, the reception says the community was ready for this.