The basic steps work the same way in most video editors

To add audio to a video, you import your video file into a video editor, then import an audio file separately and place it on the timeline below or alongside your video track. Most editors let you drag the audio file directly onto the timeline, adjust when it starts and stops, and control its volume. The audio and video stay linked to that timeline until you export them together as a single file.

The specific steps change depending on which editor you use — DaVinci Resolve works differently from Adobe Premiere, which works differently from CapCut — but the underlying process is identical. You need a video editor that supports multiple tracks, an audio file in a common format like MP3 or WAV, and about five minutes to position everything correctly.

Key Takeaways

  • Most video editors let you drag an audio file directly onto the timeline below your video track, then adjust its start time and volume.
  • Audio files should be in a common format like MP3, WAV, or AAC; if your file won't import, converting it to MP3 usually solves the problem.
  • You can layer multiple audio tracks — for example, background music plus voiceover plus sound effects — and adjust each one's volume independently.
  • After positioning your audio, export the video and audio together as a single file in your chosen format, which combines them permanently.

Importing your video and audio files into the editor

Open your video editor and create a new project. Most editors ask you to choose a frame rate and resolution at this point — match whatever your video file uses, or accept the editor's default if you are unsure. Then import your video file by going to File > Import or by dragging the file directly into the editor window.

Next, import your audio file the same way. Some editors have a separate audio import option; others let you import audio through the same menu as video. If your audio file does not appear in the import dialog, check that it is in a supported format — MP3, WAV, and AAC work in nearly every editor. If you have a file in an unusual format like FLAC or OGG, convert it to MP3 first using a free tool like Audacity or an online converter.

Placing audio on the timeline and syncing it with video

Drag your video file onto the main timeline. It will appear as a track with both video and audio — most editors show video on top and audio waveforms below. Then drag your audio file onto the timeline below the video track, or into a separate audio track if your editor has one.

Look at where your audio starts relative to the video. If the audio should begin at the same moment the video starts, align them at the same point on the timeline. If the audio should start later — for example, a voiceover that begins five seconds in — drag the audio file to the right until it lines up with the five-second mark on the timeline ruler. Most editors show you a time code as you drag, so you can position it precisely.

If your audio is longer than your video, it will extend past the end of the video track. That is fine — when you export, the editor will stop recording once the video ends. If your audio is shorter than your video and you want silence at the end, the editor will leave that space empty, which is also fine.

Adjusting volume and adding fades

Click on the audio track to select it. Most editors show a horizontal line running through the middle of the audio waveform — this is the volume control. Drag this line up to make the audio louder or down to make it quieter. You can click on the line at different points to create volume changes at specific moments, so the audio could start quiet, get louder, then fade out at the end.

To create a fade-in or fade-out, look for the corners of the audio clip on the timeline. Drag the top-left corner inward to fade in (audio starts silent and gets louder), or drag the top-right corner inward to fade out (audio gets quieter and ends silent). The distance you drag determines how long the fade takes — a small drag creates a quick fade, a large drag creates a slow one.

If you have multiple audio tracks — for example, background music plus a voiceover — adjust each one independently. Select one track, change its volume, then select the other track and change its volume. This lets you balance them so both are audible without one drowning out the other.

Replacing or removing the original video audio

Most videos come with their own audio track — dialogue, background noise, or music recorded at the same time as the video. When you add a new audio file, you now have two audio tracks playing at once, which usually sounds messy.

To remove the original audio, click on the video track itself (not the audio track below it) and look for a mute button or audio toggle. In DaVinci Resolve, right-click the video track and choose Mute Audio. In Adobe Premiere, click the speaker icon next to the video track. In CapCut, select the video clip and toggle off the audio option. Once muted, the original audio will not play when you export, but the video itself stays intact.

If you want to keep parts of the original audio and add new audio on top, you do not need to mute anything — just adjust the volume of each track so they blend well together.

Exporting your video with the new audio

Once your audio is positioned and volumes are set, go to File > Export or File > Render to save the video. Choose your output format — MP4 is the most common choice and works on nearly every device and platform. The editor will ask you to choose a location and filename, then begin combining your video and audio into a single file.

Export time depends on your video length and your computer's speed. A five-minute video might take two to ten minutes to export. Once the export finishes, play the file in your media player to confirm the audio is there, positioned correctly, and at the right volume.

If the audio is out of sync — for example, the audio starts before the video or lags behind it — go back to the editor, adjust the audio track's position on the timeline, and export again. Small timing fixes usually take less than a minute to make.

Working with multiple audio tracks and sound effects

You can add as many audio tracks as you need. A typical project might have background music on one track, a voiceover on another, and sound effects on a third. Each track plays at the same time, and you control each one's volume independently.

To add a second audio file, import it the same way you imported the first one, then drag it onto a new audio track below the first. Position it on the timeline so it starts when you want it to. If you want the second audio to fade in while the first one fades out, adjust the volume lines on each track so they cross at the moment you want the transition to happen.

Most editors let you add as many tracks as your computer can handle, though working with more than four or five audio tracks at once can slow things down. If your editor feels sluggish, export a version with just the audio tracks combined, then import that combined audio file back in as a single track to speed things up.

Frequently Asked Questions

What audio file formats work in video editors?

MP3, WAV, and AAC work in nearly every video editor. Some editors also support FLAC, OGG, and M4A. If your file is in an unsupported format, convert it to MP3 using Audacity (free, works on Windows, Mac, and Linux) or an online converter. The conversion takes a few seconds and does not change the audio quality noticeably.

Can I add audio that is longer than my video?

Yes. The audio will extend past the end of the video on the timeline, but when you export, the editor stops recording once the video ends. The extra audio will not be included in the final file. If you want the audio to continue after the video ends, you would need to extend the video with a still image or blank frame first.

How do I fix audio that is out of sync with the video?

Go back to the editor, click on the audio track, and drag it left or right on the timeline to shift when it starts. Most editors show a time code as you drag, so you can position it precisely. Export again and check the result. If it is still off, adjust it again — small timing fixes usually take only a few tries.

Can I use copyrighted music as background audio?

That depends on where you plan to post the video. YouTube, TikTok, and Instagram have copyright detection systems that flag copyrighted music and may mute it, claim ownership, or block the video in certain countries. If you want to avoid this, use royalty-free music from sites like Pixabay, Pexels, or Epidemic Sound, or create your own audio.

What if my audio sounds too quiet or too loud after I export?

Go back to the editor, select the audio track, and adjust the volume line up or down. If the audio is too quiet, drag the line up; if it is too loud, drag it down. Export again and check the result. Most editors let you preview the audio before exporting, so you can hear how loud it will be without waiting for the full export to finish.