Audacity 4.0 rebuilds interface on Qt and ships new clip-editing model

A generational rebuild, not an incremental update

Audacity, the long-running open-source audio editor, has released version 4.0. According to the release notes published on the project's GitHub repository, the update rebuilds the application's interface on the Qt framework and introduces a new clip-editing model, alongside a broad set of quality-of-life changes. Most Audacity 3 workflows still exist, but the notes warn that some controls have moved or behaved differently.

Clips become first-class objects

The centerpiece of the release is how clips are handled. Clips can now be selected directly by clicking a header, and Shift-clicking selects several at once, so moving, trimming and time stretching can be applied to every selected clip in one action. Clips can also be grouped, and groups stay together when moved, copied, pasted or duplicated.

Placement rules have loosened as well. Clips can move between mono and stereo tracks, and dragging one clip over another now replaces the overlapped portion rather than blocking the move. Splitting gets a dedicated tool: press or hold S and click the waveform or a clip header, with related operations such as split-cut, split-delete, splitting at silences and splitting to a new track exposed as commands.

Pasting is more forgiving. The release notes say Audacity can create a track when one is needed, adapt compatible channel layouts, and paste audio files taken from the operating-system clipboard. Alignment guides, sample-boundary snapping and per-project snap settings have been added or expanded.

Interface rebuilt on Qt

The interface itself was rewritten on Qt with native high-DPI rendering. Toolbars and panels can be moved, docked, floated, shown or hidden, and layouts can be saved as Workspaces; the release ships with Modern, Classic and Music presets. Light, dark and high-contrast themes are available, along with accent colors, track colors and several clip styles. A new Home screen lists recent projects with preview thumbnails.

Notably, the separate Select, Envelope, Draw and Multi-tool modes are gone. Their functions became context-sensitive instead: volume envelopes appear in Clip gain mode, sample drawing becomes available when zoomed to individual samples, and splitting happens via the S key. Sync-Lock has also been removed, replaced by explicit delete, cut and paste variants that either leave a gap or shift later material to preserve timing. Track and effect parameters now use consistent rotary controls with fine adjustment and a double-click reset.

Playback, recording and effects

On the playback side, the playhead stays visible during navigation and can be dragged to a new position, and playback can seek without stopping. Recording can begin anywhere on the timeline and produces a clip at that position. Punch and Roll, lead-in recording, latency compensation, software playthrough and per-track input monitoring were all rebuilt for the new interface.

The Audio Setup section now includes system-default devices, refreshable device lists and custom channel mapping, and the application can follow operating-system device changes automatically. Official Windows builds include ASIO playback and recording support. Track headers gained live playback and recording meters, and preset handling is now consistent across built-in, destructive and realtime effects.

Supported plugin formats are VST3, Nyquist, LV2 on Linux and Audio Units on macOS, and Audacity can display generated controls when a plugin's own interface is unavailable. The spectrogram view has been redesigned with clearer guides and rulers plus faster rendering. The project has also replaced its logo.

A new project format

Audacity 4 introduces the .aup4 project format. Existing .aup3 projects open and convert to .aup4 without altering the original file, but converted projects cannot be saved back to .aup3. Older .aup projects can be imported, and project files now store preview thumbnails along with the version's additional clip and appearance data.

What is missing at launch

Several Audacity 3 features are not yet present in 4.0, according to the release notes, though work is ongoing: Time Tracks, Note/MIDI tracks, the Mixer, Macro Manager and the scripting pipe, VAMP and LADSPA plugin hosting, and Play-at-speed. The team also acknowledges that some exporting and rendering features, analyzers and effects are absent from this release. A post-release update added SoundTouch and sbsms third-party libraries to the source tarball.

Why it matters

Audacity remains one of the most widely installed open-source audio tools, and 4.0 is a platform-level rewrite rather than a feature drop. The Qt migration brings high-DPI rendering, a modern docking interface and themes, while the clip-selection and grouping model moves the editor closer to the editing patterns of full digital audio workstations. The trade-off is real: users who depend on MIDI tracks, macros, scripting or LADSPA plugins may need to stay on 3.x until those return, and the one-way .aup3 to .aup4 conversion means anyone with an archival workflow should keep their original project files intact.