Record screen with audio: microphone and shared audio setup

Understanding audio recording: microphone vs system audio

Microphone audio comes from an input device. Shared audio comes from the tab, window, or screen selected in the browser, but only when the browser and operating system provide an audio track for that surface.

Microphone recording is the most common audio source for screen recordings. Current desktop browsers generally support it, but access still depends on site permission, device policy, an available input, and whether another application has exclusive control of the device.

Whole-system audio refers to the computer's output, while tab audio is limited to a selected browser tab. A share picker may offer one, the other, or no shared-audio option depending on the selected surface and platform.

The distinction matters because the sources use different browser APIs. Microphone access uses getUserMedia; shared audio is an optional part of the stream returned by getDisplayMedia. Permission, policy, and device availability can affect both.

Most screen recordings use microphone-only audio: you are narrating what you are demonstrating. System audio is needed when the demonstration itself produces sound you want to capture—recording gameplay, demonstrating audio software, capturing a video call (with participants' permission), or showing how a sound effect triggers in an application.

Setting up microphone recording

Enable the Microphone toggle before starting. The browser then requests access to its current default input, and Screencast includes the returned track in the recording.

The Microphone toggle is on by default in Screencast, so if you do nothing, microphone audio will be included. If you want to record without narration, toggle it off before starting. Once recording begins, this cannot be changed—you cannot add or remove microphone audio mid-recording.

Permission persistence varies by browser and policy. If access was denied, open the browser's site settings, restore microphone permission, reload, and try again.

Microphone level is controlled outside Screencast. Make a short recording at your normal speaking volume and listen for quiet audio, clipping, or the wrong input device before recording the real take.

Use headphones while recording to prevent echo and feedback. If your microphone picks up the sound from your speakers (system audio, video playback, etc.), it will be recorded along with your voice, creating an echo effect. Headphones isolate your voice from system sounds, producing a cleaner recording.

If several inputs are connected, choose the intended device in your operating-system or browser settings before starting. Screencast currently requests the browser's default input rather than presenting its own device selector.

System audio support by browser and operating system

Shared audio is offered by the browser for particular share surfaces. Chromium browsers commonly support tab audio, while whole-system or window audio depends on the browser, operating system, and the option selected in the share picker.

On Windows, current Chromium browsers often offer a system-audio option when an entire screen is selected. Tab sharing can offer audio from the selected tab. The exact checkbox and available source are controlled by the browser and may be restricted by enterprise policy.

On macOS, Chromium browsers commonly offer audio for a shared browser tab, but whole-system audio may not be offered. Safari and Firefox have different capture capabilities and should be tested with the exact source you intend to record.

On Linux, results depend on the browser and audio stack. PipeWire-based systems can expose more capture options than older configurations, but Screencast cannot force an audio track when the browser returns video only.

The System audio toggle is a request to the browser, not a guarantee. After the share picker closes, Screencast can record only the tracks the browser returned. A short test recording is the reliable way to confirm the selected surface includes audio.

If system audio is essential for your recording and your browser or operating system does not support it, consider using desktop recording software (OBS Studio on Windows/Mac/Linux, Screenshot.app on Mac, Xbox Game Bar on Windows) which have deeper system integration and more reliable system audio capture.

Recording browser tab audio

A browser may offer an option to include audio from a shared tab. When it does, enable that option in the share picker and verify the result with a short test recording.

Tab audio is neither whole-system audio nor microphone audio. It is an optional track associated with the browser tab chosen in the share picker.

To request it, turn on System audio in Screencast, select a browser tab in the share picker, and enable the picker's audio option when present. If the browser returns the tab's audio track, Screencast mixes it with the microphone when the microphone is also enabled.

This is particularly useful for recording web-based demonstrations, capturing online meeting or webinar audio (with permission), recording streaming content for review, or demonstrating web applications that include audio elements. Tab audio keeps the recording focused on just that tab's content.

Tab audio is intended to exclude other tabs, desktop applications, and system alerts. If you need broader audio, check whether the browser offers audio for an entire-screen share on your operating system; that option is not universal.

Tab-audio support and share-picker wording change across browsers. Current Chrome or Edge is the most predictable choice for this workflow, but the returned stream should still be tested before an important recording.

Audio quality and recording settings

Screencast lets the browser choose the audio sample rate, codec, bitrate, and channel layout. The app does not promise a fixed 48 kHz or 128 kbps setting.

Audio quality in screen recordings is typically "good enough" rather than audiophile-grade, and this is appropriate: the focus is on the visual content, with audio providing context and narration. High-fidelity audio would increase file size substantially with no perceptible benefit for typical screen recording use cases.

The recorder does not pass an audio bitrate or sample-rate override to MediaRecorder. Browser defaults can vary with the input sample rate, channel count, codec, and browser implementation. Inspect the exported file if a downstream workflow requires a specific format.

Shared audio may already be compressed at its source, and MediaRecorder encodes the final mixed stream. Do not assume that a recording is lossless or identical to the source audio.

Background noise from your microphone is not filtered or removed. Record in a quiet environment, use a directional microphone if possible, and avoid recording near fans, air conditioning, or other noise sources. Some external microphones have built-in noise cancellation or cardioid pickup patterns that reduce background noise.

Audio and video are passed to the same MediaRecorder stream, but overloaded devices and browser encoder problems can still produce drift or gaps. If synchronization matters, test with the intended resolution, audio sources, and recording duration.

Recording both microphone and system audio together

Enable both toggles before starting. Screencast mixes the microphone with shared audio only when the browser successfully returns both tracks.

Combined audio is useful when you are narrating over application sounds, demonstrating audio software, recording gameplay with your commentary, or showing how sound effects work in an application. Both your voice and the system audio will be captured and mixed into a single audio track in the recording.

The mixing happens automatically and Screencast has no per-source level controls. Adjust the source and microphone levels before recording, then confirm their balance with a short test because platform capture levels vary.

Be aware that if system audio is loud and your microphone is sensitive, the microphone may pick up sound from your speakers (echo/feedback) in addition to system audio being captured directly. Always use headphones when recording with both microphone and system audio to prevent this. Headphones isolate your microphone from speaker output.

On some systems, particularly macOS, capturing both microphone and system audio can be unreliable. If you find that system audio is not being captured when both are enabled, try recording with system audio only, then record a separate microphone-only track, and combine them in a video editor. This gives you more control and works around browser/OS limitations.

For professional recordings where audio quality is critical, consider recording audio separately using dedicated audio recording software (Audacity, GarageBand) while screen recording silently, then combining them in post-production. This gives you much more control over audio levels, noise reduction, and editing.

Troubleshooting audio recording issues

Most audio problems stem from denied permissions, wrong input/output device selection, or system audio configuration. Check browser permissions, verify your microphone and speakers are selected correctly, and ensure system audio is supported on your platform.

If there is no microphone audio in your recording: check that you enabled the Microphone toggle before starting, verify your browser has microphone permission (check site settings or the lock icon in the address bar), confirm your microphone is not muted in your operating system's audio settings, and test your microphone in another application to ensure it works.

If there is no shared audio: confirm the System Audio toggle was enabled before starting, then check whether the browser share picker offered an audio option for the surface you selected. On Chromium, try sharing the specific browser tab that produces the sound. Whole-system audio may be available on some Windows configurations but should not be assumed on macOS or Linux.

If audio is extremely quiet: check your microphone input level in system audio settings and increase it, verify your system audio output level is reasonable (30-70% volume), and ensure nothing in your audio chain (microphone, interface, system settings) is muted or set to minimum.

If audio is distorted or crackling: lower your microphone input level to prevent clipping, reduce system audio output level if it is near 100%, close other applications that might be consuming audio resources, and check that your microphone is not physically damaged or having connection issues.

If audio is out of sync with video: this usually indicates your system was overloaded during recording. Close unnecessary applications, record at a lower resolution, avoid recording while doing CPU-intensive tasks, and ensure your computer is plugged in (not on battery power). If this happens consistently, your hardware may not be powerful enough for real-time recording at the resolution you selected.

If tab audio does not work: ensure the tab is playing audio before sharing, check that it is not muted, and confirm the browser share picker included an audio checkbox or label. Try a current Chrome or Edge release if your usual browser does not expose an audio track.

Audio recording for specific use cases

Different recording scenarios require different audio approaches. Tutorials need clear narration (microphone-only), game recordings need both gameplay audio and commentary (microphone + system audio), and bug reports often need no audio at all.

Tutorial and educational recordings: use microphone-only audio. System audio is usually just distracting background noise. Focus on clear narration explaining what you are demonstrating. Record in a quiet space, speak clearly at a moderate pace, and pause briefly between major steps. This produces the most professional-sounding instructional content.

Game recordings and gameplay videos: use both microphone and system audio. Viewers want to hear the game audio (music, sound effects, dialogue) alongside your commentary. Balance the levels so your voice is clearly audible over the game audio—if necessary, lower the game's audio in its settings before recording.

Software demonstration and product tours: microphone-only unless the software itself produces important audio cues. Most productivity software demonstrations do not need system audio—viewers are watching what you are clicking and hearing your explanation.

Bug reports and issue reproduction: often no audio is needed. If you are showing a visual bug or broken workflow, the video alone is sufficient. Adding microphone narration can be helpful ("Notice how the button doesn't respond when I click it"), but system audio is rarely relevant.

Meeting and presentation recordings: if recording a video call or webinar, tab audio captures the other participants' voices if you share the meeting tab. Add microphone audio if you are also speaking. Note that recording others requires their consent—do not record calls without permission.

Music and audio software demonstrations: system audio is essential. Consider recording system audio only without narration, or record your spoken explanation separately and combine them later. This ensures the audio being demonstrated is captured clearly without your voice overlapping the sounds you are trying to show.