An abrupt audio cutoff is one of the most jarring mistakes in video editing. After Effects gives you precise control over audio volume through keyframeable properties, so creating a smooth fade out takes only a few clicks once you know where to look. This guide walks through the primary method using Audio Levels keyframes, a quick alternative with the Stereo Mixer effect, and fixes for the most common problems editors run into.
How to Fade Out Audio in After Effects (Step-by-Step)
The Fastest Way: Keyframe Audio Levels in the Timeline
Keyframing the Audio Levels property is the standard approach in After Effects. It gives you frame-level control over exactly when the fade starts and ends, and it works on any audio layer in your composition.
Step 1: Select Your Audio Layer and Expand Audio Properties
Click on your audio layer in the Timeline panel to select it. Press the A key on your keyboard to reveal the Audio properties. The Audio Levels row will appear directly below the layer name. If nothing appears, confirm the layer contains actual audio content and check that the speaker icon on the left side of the timeline is not toggled to mute.
Step 2: Set a Keyframe at the Fade Start Point
Move the playhead to the point in the timeline where you want the fade to begin. Click the Stopwatch icon next to Audio Levels. This activates keyframing and places your first keyframe at the current time. The value should reflect your normal playback volume, typically 0 dB.
Important: The Stopwatch must be activated before you make any value changes. If you adjust the level without clicking the Stopwatch first, After Effects applies that value globally rather than recording it as a keyframe over time.
Step 3: Set the End Keyframe to Silence (−100 dB)
Move the playhead forward to the point where you want the audio to reach complete silence. Click the Add Keyframe button (the small diamond icon between the navigation arrows next to Audio Levels), or simply type a new value directly into the Audio Levels field. Set the value to −100 dB.
Note on silence: After Effects shows absolute silence as −∞ dB in the audio waveform display, but the input field accepts −100 dB as the functional equivalent. Using −100 dB is consistent and reliable across all versions of After Effects CC.
Step 4: Apply Easy Ease for a Natural Fade Curve
Select both keyframes by clicking the first, holding Shift, and clicking the second. Press F9 to apply Easy Ease. This changes the interpolation from a mechanical linear drop to a gradual curve that tapers smoothly toward silence, which is far more natural to listeners.
To refine the curve further, open the Graph Editor (click the Graph Editor icon at the top of the Timeline panel) and drag the bezier handles on the Audio Levels value graph to control the exact shape of the fade.
Make It Sound Natural: Understanding Keyframe Interpolation
Linear keyframes drop volume at a constant rate per frame. Because human hearing is logarithmic, this type of fade often sounds robotic or too sudden near the end of the fade. Easy Ease front-loads the fade with a slow, gradual drop and ramps toward silence, which mirrors how audio naturally decays in a real space.
Make It Sound Natural: Understanding Keyframe Interpolation
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Linear: Volume decreases at the same rate throughout. Often sounds mechanical and abrupt in the final frames.
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Easy Ease (F9): Volume change starts slowly and accelerates toward silence. Produces a smooth, natural-sounding result with no extra work.
If Easy Ease alone does not match the feel you need, open the Graph Editor and extend the outgoing bezier handle on your first keyframe to lengthen the gradual portion of the fade.
Alternative Method: Using the Stereo Mixer Effect
The Stereo Mixer effect is useful when you want to control stereo panning and fade volume in a single pass, or when Audio Levels behaves unexpectedly on pre-composed or imported layers.
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Select your audio layer in the timeline.
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Go to Effect > Audio > Stereo Mixer.
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In the Effect Controls panel, locate Left Level and Right Level.
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Move the playhead to the fade start point and click the Stopwatch next to both Left Level and Right Level to place opening keyframes at your current volume percentage.
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Move the playhead to the fade end point and set both Left Level and Right Level to 0%, which equals silence within this effect.
Apply Easy Ease (F9) to all four keyframes for a smooth result. Keep in mind that the Stereo Mixer uses a percentage scale rather than decibels, so 0% here represents silence and 100% represents the unmodified signal level.
Quick Tip: Fade Out Audio with an Expression (Advanced)
For editors who need the same fade out applied across many layers without placing keyframes manually, expressions offer a repeatable solution. Hold Alt (Windows) or Option (Mac) and click the Audio Levels Stopwatch to enter expression mode, then enter:
linear(time, outPoint -1, outPoint,0,-100)
This automatically fades from 0 dB to −100 dB over the final one second of whatever layer the expression is applied to. It is most practical when building composition templates or batch-processing a large number of audio layers.
Common Mistakes and Quick Fixes
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The audio does not fade at all: The Audio Levels value was changed before the Stopwatch was activated. Delete any unintended keyframes, click the Stopwatch to activate it, then place your keyframes in the correct sequence.
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The audio jumps abruptly to silence instead of tapering: Both keyframes are placed at the same time position, or the −100 dB keyframe appears before the 0 dB keyframe in the timeline. Check the keyframe order and make sure there is visible spacing between them.
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Audio Levels is not visible in the timeline: The layer may not be fully expanded, or the mute toggle (speaker icon) is active. Press A with the layer selected to reveal Audio properties directly, and confirm the mute icon is off.
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The fade still sounds robotic: Linear interpolation is still active on one or both keyframes. Select both keyframes and press F9 to convert them to Easy Ease.
Frequently Asked Questions
How do I fade out audio at the very end of a clip in After Effects?
Move the playhead to the clip’s out-point in the timeline. Place your second Audio Levels keyframe at that position and set the value to −100 dB. Your first keyframe, set to 0 dB a few seconds earlier, marks where the fade begins. After Effects interpolates the volume drop smoothly between the two points.
Can I fade in and out on the same audio layer?
Yes. Use four keyframes on the Audio Levels property: set the first to −100 dB at the layer’s start, the second to 0 dB where full volume should begin, the third to 0 dB where the fade out starts, and the fourth to −100 dB at the end. Apply Easy Ease to all four keyframes for smooth transitions in both directions.
Why can’t I hear my audio during playback in After Effects?
After Effects requires a RAM Preview to play back audio in sync with the timeline. Press 0 on the numeric keypad to start a RAM Preview with audio enabled. If you still hear nothing, check that the audio layer’s mute icon (the speaker symbol in the timeline) is not active, and verify that audio output is enabled in your composition settings.
Conclusion
Keyframing Audio Levels is the fastest, most reliable way to fade out audio in After Effects, and Easy Ease handles the curve work with a single keystroke. From here, natural next steps include syncing your audio fades to specific video cuts, using layer markers to time music transitions, and confirming your composition exports with audio intact. If you are building a full production workflow from field recording through post, starting with clean source audio from a reliable wireless mic like the Hollyland LARK MAX 2 means less corrective work before you ever open After Effects.
