REAPER is a powerful but sensible Windows application designed for the recording, arrangement, editing, mixing and rendering of audio. REAPER provides a flexible but easy to use interface that is equally suited to amateurs and professionals alike.

REAPER is a small and lightweight application (the installer is less than 1 megabyte, which includes many effects and a sample project). REAPER is designed with both processing and user interaction speed in mind.

Basic features:

• Support for an unlimited number of audio tracks.
• Audio tracks are all fully routable (multiple inputs, outputs).
• Volume, pan controls and envelopes per track.
• Supports audio processing plug-ins (DirectX, DXi, VST, VSTi, and Jesusonic) with automation, easy chain manipulation and editing.
• Pitch shifting and time stretching.
• Fast, reasonable and usable Windows-style UI, working well on both low and high resolutions or multiple monitors.
• ASIO, Kernel Streaming, WaveOut, and DirectSound support for playback and recording.
• Reads WAV, OGG, MP3 and MIDI files, records WAV and MIDI files.
• Can render to WAV, OGG, MP3 if lame is installed.
• Full SMP support (can utilize 2 or more processors).
• Multi-layer undo/redo support.
• User creatable color themes.

Advanced features:

• Unlimited send/receives per track, with configurable parameters (pre-fx, post-fx, volume/pan adjustment/envelopes, mix to mono, phase, etc.).
• Any track can act as a bus, for routing flexibility.
• Tracks can have one or more (mono or stereo) hardware sends, for analog mixing capability.
• Fully routable/FX-able folder tracks that can contain group tracks.
• Item grouping.
• Ripple editing.
• Grid/snap support with configurable options.
• Markers.
• Unlimited takes per media item.
• Auto punch-in/punch-out functionality.
• Automatic record monitoring modes.
• Selection length granularity options as well as grid snapping.
• Tempo envelope (for grid lines/snapping/ruler), play-speed envelope.
• Project consolidation/export options (for rendering all or parts of any number of tracks to WAV, etc.).
• A UI and architecture that allows you to easily cut loops of many tracks simultaneously, without having to write them to disk.
• Support for plug-in generated media (such as click tracks, etc.).
• Project tempo envelopes for variable tempos in track, grid/snapping that supports variable tempos.
• 64-bit floating point sample pipeline for high quality.
• Advanced recording and monitoring options; examples:
  - You can route multiple tracks (inputs and/or media items) into a bus, and record THAT mixed down version.
  - You can record the input signal, or record the post-FX, post-track-render signal.
  - You can switch recording sources on the fly, even while recording.
  - You can arm/disarm tracks' inputs while playing or recording.

Other features:

• Human readable, human editable, backwards and forwards compatible project file format.
• Options to build peaks for recorded files on the fly.
• Lots of control for the user to specify where recorded files go, etc., when dealing with many projects.
• Template support to make it easy to load a project template and save it as a new project when you begin.
• Input/output channel name aliasing (why view your inputs as "MOTU 896: Analog 1" when you could have them be "Vocal Mic", etc.).
• Options for automatically backing up project files to alternate paths, time-stamped versions, etc.

New in v3.05

• Significant audio processing performance improvements, especially in larger projects.
• FX processing improvements for all Cockos plugins.
• Processing performance improvements for MIDI-only tracks.
• Significant graphics optimizations.
• Pasting items in large projects is faster.
• Fixed dragging items vertically across multiple tracks.
• Media explorer remembers the last directory visited when reopened.
• Global automation override is saved with project.
• JS sysex support: midisyx(frameoffset,msgbuf,len).
• FX parameter adjustment undo point is set immediately if the plugin informs the host the move is done.
• Fixed random creation of different-length takes in loop recording.
• Faster bulk-arming of tracks via action.
• Seek is less likely to unnecessarily scroll the view.
• Properly resize last track in folder when compacting.
• FX quick-add menu contents are sorted alphabetically.
• Safer VST unloading while playing.
• Use envelope lane button hover states.
• Don't allow dragging a folder track into its own children.
• Copy MIDI item editor settings (note shape, etc) when copying MIDI items.
• Don't autoclose audio device when media explorer is previewing.
• Fixed waveout/directsound issues on failed initialization.
• Better folder remembering on render/consolidate, better default record path (rather than path to app).
• MIDI editor: option to set default color map (in prefs/media/midi).
• Support for mcp_master_sendlist_* theme images.
• ReaTune updates for multiple project and better take-fx support in manual mode, slight visual overhaul.
• Color-themeable fade area shading for media items.
• Color-themeable blinking edit cursor.
• Optional color-themeable play cursor (with width control).
• Themes can set blend mode on fade handle edges/snap offset drawing.
• More efficient time selection highlight drawing in default theme.
• Fixed action for toggle recarm on all selected tracks.
• Better cue label positioning for stereo items etc.
• Actions to toggle item normalize/multiple item normalize, un-normalize.
• Special-case mutexing for ET-200/Rez/Oatmeal, generalizable on request for other plug-ins.
• Will now prompt you to select an audio device if you have not yet selected one.
• OSX: better view of some unthemed windows in docker.
• OSX: better AU initialization for some plugins.
• Improved tempo/time signature marker editing behavior.
• Open file in external editor supports unicode filenames.
• Custom toolbar icon assigned to "bounce live output to disk" will light up while recording.
• Preference whether to auto-show FX window after adding via quick-add menu.
• Warn if unable to save changes because project file is read-only.
• Fix for problems unloading plugins that run message loop during effClose (i.e. Guru).
• Fixed bug with mixed native/OS text rendering colors being incorrect.