How to Record System Audio in Audacity Using WASAPI Loopback

WASAPI loopback lets Audacity capture the sound your Windows computer sends to a speaker or headset, such as a browser tab, a media player or the other side of a video call, without a cable or a virtual mixer. This guide covers setting it up, checking the recording and fixing the errors people most often hit.

Before you start

• A Windows computer. WASAPI is a Windows audio interface, so the loopback option does not appear on macOS or Linux.
• A reasonably current Audacity release installed from the official project. Loopback support has existed for many versions, but the toolbar layout differs between older and newer releases, as described below.
• The output device you want to capture, for example speakers, a USB headset or an HDMI display, connected and working in Windows before you open Audacity.
• Permission to record the material. Capturing a call or a stream may require consent from other participants or the rights holder.

Audacity records and processes the audio locally on your computer; no online service is involved in the capture itself. Where the project and exported files end up depends on the folders you choose, so check the save location if the recording contains private conversations.

Step-by-step instructions

Work through these steps in order. Each setting can be switched back afterwards if you normally record from a microphone.

• Start playing the audio you want to capture, or have it ready to play, so you can see the meters respond while you configure Audacity.
• Open the device settings. In Audacity 3.2 and later, click the Audio Setup button on the toolbar. In older versions, use the drop-down lists on the Device Toolbar.
• Set the audio host to Windows WASAPI. Loopback devices are not listed under MME or Windows DirectSound.
• For the recording device, choose the output device you are listening through, the entry that carries the word loopback in its name. Pick the one that matches the device actually playing the sound; capturing from the wrong output device gives a silent track.
• Set recording channels to 2 (Stereo) unless you specifically need mono.
• Check that Software Playthrough is turned off (Transport menu, Transport Options). With loopback, playthrough sends the captured audio back to the same output and can cause echo or feedback.
• Set the project sample rate to match the format Windows uses for that output device. You can see that format in the Windows sound settings, in the advanced properties of the playback device. A mismatch is a common reason the recording refuses to start.
• Click Record, play the source audio and watch the recording meter. Click Stop when you are finished.

The input level for a loopback capture comes from the playback signal itself, so the meter reflects how loud the source application is playing. If the meter reaches the top and shows clipping, lower the volume in the source app and record again rather than trying to repair distortion afterwards.

Loopback captures the full mix sent to that output device, including notification sounds and any other app that plays at the same time. Mute or close sources you do not want in the recording. Your microphone is not included, because Audacity records from one input device at a time; capturing both sides of a call with your own voice requires a different routing setup.

Check the output

• Play the new track back from the start and listen for the whole length, not just the first seconds.
• Look at the waveform. A flat line throughout means the wrong loopback device was selected or the source was muted.
• Compare the track length with how long you actually recorded. Some setups deliver no data while nothing is playing, so quiet passages may be shortened or missing; if timing matters, keep the source playing continuously or verify the gaps.
• Confirm the track is stereo if you selected two channels, and that the left and right sides sound correct.
• Export to the recording format you need from the File menu. WAV keeps the captured quality without lossy encoding; MP3 or another compressed format produces a smaller file, and its bitrate setting controls the trade-off between size and quality.

The recording cannot exceed the quality of what the computer was playing. If the source was a low-bitrate stream or a call with compressed audio, a high sample rate or lossless export preserves that signal faithfully but does not add detail that was never there.

Common problems and next steps

No loopback device in the list: make sure the host is set to Windows WASAPI, connect the output device, then use Rescan Audio Devices from the Transport menu or the Audio Setup menu. Restart Audacity if the device was plugged in while it was open.

Error opening the recording device or an invalid sample rate message: change the project rate to the default format shown for that playback device in Windows, or change the device format in Windows to a value Audacity is set to. Both sides must agree.

The track records but stays silent: check that the selected loopback entry matches the device playing the audio. Switching between speakers and a headset in Windows changes which loopback device carries the sound, so repeat the selection after any switch.

Echo, doubled sound or feedback: turn off Software Playthrough. If you also monitor through a separate tool, make sure it is not sending the recorded signal back to the same output.

Background noise or system sounds in the capture: loopback records exactly what the output device receives, so the fix is at the source. Silence notifications and other apps during the recording; noise in the original stream can only be reduced afterwards with Audacity's editing effects, with some loss of quality.

Bluetooth or HDMI outputs behaving differently: such devices may switch formats or channel counts depending on what is playing. If capture is unreliable, try a wired output device, confirm its format in Windows and select its loopback entry again in Audacity.