The basic steps work the same way in most editors

To add audio to a video, you import both files into your editor, place them on separate tracks in the timeline, and adjust the volume so both play together. The specific steps depend on which editor you use, but the principle is identical: your video and audio sit side by side on the timeline, and you control when each starts, how loud it plays, and when it stops.

Most editors let you drag and drop files directly onto the timeline. Some require you to import them first through a File menu. Either way, once both are in the timeline, you can move them independently, trim them to length, and fade one in or out while the other plays.

The hardest part is usually syncing — making sure the audio starts at the right moment. If your video already has audio (like dialogue or ambient sound), you will need to decide whether to keep it, replace it, or mix both together. Most editors let you mute the original video track while keeping the new audio, or lower the original volume so both are audible.

Key Takeaways

  • Import your video and audio files into the timeline as separate tracks, then adjust their timing and volume to work together.
  • If your video already has audio, you can mute it, lower its volume, or keep both — depending on what your project needs.
  • Syncing means making sure the audio starts at the right frame; most editors let you drag audio left or right on the timeline to line it up.
  • Fade in and fade out controls let you prevent jarring starts and stops, especially useful when mixing multiple audio tracks.
  • Export settings determine the final audio quality; match your audio bitrate to your video quality to avoid wasting file size.

How to sync audio to video in DaVinci Resolve

DaVinci Resolve is free and handles audio syncing well. Drag your video into the timeline first, then drag your audio file below it on a separate track. The video track and audio track will sit parallel to each other.

If the audio needs to start later than the video, click and drag the audio clip to the right on the timeline. If it needs to start earlier, drag it to the left. The playhead (the vertical line that shows where you are in the timeline) will help you see exactly where each clip begins. Play through the section where they meet to confirm they line up the way you want.

To mute the original video audio, right-click the video track and select Mute Audio Track. To lower its volume instead, click the audio portion of the video clip and drag the volume slider down. You can also use the keyframe tool to fade the original audio out gradually while your new audio fades in.

How to sync audio to video in Adobe Premiere Pro

In Premiere Pro, drag your video to the Video 1 track and your audio to the Audio 1 track below it. Both will appear in the timeline at the same horizontal position — the left edge of the timeline represents the start of your project.

To move the audio earlier or later, click it and drag it left or right. Premiere Pro shows you the exact frame number as you drag, which helps if you need precision. You can also right-click the audio clip and choose Speed/Duration to see the exact start time in numbers.

To mute the video's original audio, click the speaker icon on the Video 1 track header. To adjust volume, select the audio clip and use the Effect Controls panel on the right, or drag the volume line that appears across the clip itself in the timeline.

How to sync audio to video in CapCut

CapCut is mobile-first and simpler than desktop editors. Import your video, then tap the plus icon to add audio. CapCut will place the audio on a separate track automatically.

To move the audio to a different point in the timeline, tap and hold the audio clip, then drag it left or right. The timeline shows you where it will land. To mute the original video audio, tap the video track, then toggle off the audio option.

CapCut's volume controls are in the audio clip's menu — tap the clip, then adjust the volume slider. You can also add fade in and fade out directly from the same menu, which is faster than in desktop editors.

Handling video that already has audio

If your video already contains audio — like dialogue, music, or background noise — you have three choices: keep only the new audio, keep only the original audio, or mix both together.

To keep only the new audio, mute or delete the original video track's audio. To keep only the original, straightforward do not add new audio. To mix both, place them on separate tracks and adjust each one's volume so neither drowns out the other. A common approach is to lower the original audio to 50 to 70 percent volume, then bring the new audio in at full volume or slightly lower depending on what matters more in your project.

If the original audio and new audio start at different times, you will need to sync them separately. For example, if your video has dialogue that starts at the 5-second mark and you want to add music that starts at the beginning, drag the dialogue track to the right so it still starts at 5 seconds, and leave the music at the start of the timeline.

Adjusting volume and adding fades

Once your audio is in place, volume control is usually the next step. Most editors show a thin line running across the audio clip in the timeline — that is the volume line. Click on it to add a point, then drag that point up to increase volume or down to decrease it.

Fading in means the audio starts silent and gradually gets louder. Fading out means it starts at normal volume and gradually goes silent. Both prevent jarring jumps when audio starts or stops. In DaVinci Resolve and Premiere Pro, right-click the audio clip and look for Fade In or Fade Out options. In CapCut, tap the audio clip and find the fade controls in the menu.

A typical fade lasts 0.5 to 2 seconds depending on the project. Music usually needs a longer fade than dialogue. If you are mixing two audio tracks, fade one out while fading the other in to create a smooth transition.

Exporting video with audio

When you export, your editor combines the video and audio into a single file. The export settings control the final quality and file size.

For audio, the main setting is bitrate — measured in kilobits per second (kbps). Higher bitrate means better quality but larger file size. For most projects, 128 to 192 kbps is standard for dialogue or speech, and 192 to 320 kbps for music. Match your audio bitrate roughly to your video quality: if your video is 1080p at 5 Mbps, use 192 kbps audio. If your video is 4K at 15 Mbps, use 256 to 320 kbps audio.

Choose a format based on where the video will go. MP4 works almost everywhere. MOV is common for Mac and professional work. WebM is smaller but less compatible. Your editor will show you the bitrate and format options in the export dialog — check them before you click Export.

Frequently Asked Questions

What if my audio and video are out of sync after I export?

This usually means they drifted during playback in the editor but looked correct on the timeline. Check the sync again in the editor before exporting. Play through the section where audio and video should match (like a person speaking) and confirm they line up. If they do not, move the audio clip slightly and try again. Export a short test clip first to confirm the sync is correct before exporting the full video.

Can I add multiple audio tracks at the same time?

Yes. Most editors let you add as many audio tracks as you need. Place each one on its own track in the timeline, adjust the volume of each so they blend well, and export them all together. This is how you mix dialogue, music, and sound effects in a single video.

How do I remove the original audio from a video?

Right-click the video clip in the timeline and look for Mute Audio, Disable Audio, or a similar option. Some editors let you delete just the audio portion of a video clip while keeping the video. In others, you mute it instead. Either way, the video stays — only the sound goes away.

What audio file formats do editors accept?

Most editors accept MP3, WAV, AAC, and FLAC. Some also accept OGG, AIFF, and M4A. If your audio file does not import, try converting it to MP3 or WAV using a free tool like Audacity or FFmpeg, then import the converted file.

Do I need to worry about audio levels being too loud or too quiet?

Yes. Audio that is too quiet will be hard to hear; audio that is too loud will distort or clip. Most editors show a meter or waveform that helps you see the volume level. Aim for peaks around -6 to -3 dB (decibels) before you export. If the waveform looks very small, the audio is too quiet. If it looks like it is hitting the top of the track, it is too loud — lower the volume.