The basic process: import, position, and export

Adding audio to a video means bringing a sound file into your video editor, placing it where you want it to start, and then saving the result. Most video editors handle this the same way: you drag the audio file into a separate audio track below your video track, line it up with the moment you want it to begin, and adjust the volume if needed. The audio file and video file stay separate inside the editor until you export — that's when they combine into a single video file.

The specific steps change depending on which editor you use, but the concept is identical across all of them. You are not converting anything or doing anything complex — you are just telling the editor "play this sound at this moment" and letting it do the work when you save.

Key Takeaways

  • Audio files go into a separate audio track in your editor, positioned to start at the exact moment you want the sound to begin.
  • Most editors let you drag audio files directly into the timeline, and you can adjust volume, fade in, or fade out without touching the original file.
  • Common audio formats like MP3, WAV, and M4A work in nearly all video editors, but check your editor's documentation if you are unsure.
  • The video and audio stay separate tracks until you export, which is when they combine into a single playable file.
  • If your video already has audio (like dialogue or background noise), the new audio will play on top of it — you control which one is louder.

Finding the audio import button in your editor

Every video editor has a way to bring audio in, but the button or menu option is not always in the same place. In DaVinci Resolve, you go to File > Import > Audio. In Adobe Premiere Pro, you use File > Import or drag the file directly onto the timeline. In CapCut (the free desktop version), you click the plus sign next to "Audio" in the left panel. In iMovie on Mac, you click the audio button in the toolbar and then "Audio Browser" to find files on your computer.

If you cannot find the import option, look for a menu that says File, Import, or Media. If your editor has a file browser panel on the left or right side of the screen, you can usually drag audio files directly from your computer into that panel. This is faster than hunting for a menu once you know where to drag from.

Positioning audio to start at the right moment

Once the audio file appears in your editor, it will show up as a separate track — usually below the video track, labeled "Audio 1" or similar. The audio will have a waveform, which is a visual representation of the sound. You can see the peaks and valleys of the audio just by looking at it, which helps you line it up with what is happening in the video.

Click and drag the audio clip along the timeline to move it left or right. Moving it left makes it start earlier; moving it right makes it start later. If you want the audio to start exactly when the video starts, drag it all the way to the left edge. If you want it to start five seconds in, drag it until the left edge of the audio clip lines up with the five-second mark on the timeline ruler at the top.

Most editors show you a tooltip or highlight when you are dragging, so you can see exactly where the audio will land. Take your time with this step — getting the timing right makes the difference between audio that feels natural and audio that feels off.

Adjusting volume and adding fades

If the audio is too loud or too quiet compared to the video's existing sound, you can change its volume without re-recording or editing the original file. Right-click the audio clip and look for "Volume" or "Audio Levels." Most editors let you type in a number (like 50% or 75%) or drag a slider. You can also click directly on the audio waveform and drag a line up to make it louder or down to make it quieter.

If you want the audio to fade in slowly at the start or fade out at the end, right-click the audio clip and look for "Fade In" or "Fade Out." You can usually set how long the fade lasts — a one-second fade is common for background music, while a three-second fade works better for longer pieces. Fades make audio feel less jarring when it starts or stops.

If your video already has audio and the new audio is drowning it out, lower the new audio's volume first, then adjust from there. You want both sounds to be audible unless you are intentionally replacing the original audio entirely.

Handling audio that is longer or shorter than your video

Audio does not have to match the length of your video. If the audio is shorter, it will play and then stop — the video will continue silently unless you have other audio. If the audio is longer than the video, the extra audio will be cut off when you export, since the export stops when the video ends.

If you want audio to play for the entire video but your audio file is too short, you can loop it — most editors have a "Loop" or "Repeat" option in the right-click menu. If you want only part of the audio file to play, you can trim it by dragging the edges of the audio clip inward on the timeline. The part you drag over will not play.

If your audio file is much longer than you need, trimming it in the editor is fine, but you can also trim it before importing using a free tool like Audacity. This keeps your project file smaller and makes the editor run faster.

Exporting your video with the new audio

Once the audio is positioned and the volume is set, you export the video the same way you normally would. Go to File > Export or File > Render, depending on your editor. Choose your format (MP4 is the most common), pick a location to save, and click Export. The editor will combine the video and audio into a single file.

The export process takes time — usually a few minutes for a short video, longer for something that is several minutes or longer. Do not close the editor or unplug your computer while it is exporting. Once it finishes, you can play the file in any video player and hear both the video's original audio and the new audio you added, mixed together at the volumes you set.

Common audio formats and compatibility

Most video editors accept MP3, WAV, M4A, and AIFF audio files without any trouble. If you have audio in a different format — like OGG, FLAC, or WMA — your editor might not recognize it. If that happens, you can convert the file using a free tool like Audacity or an online converter before importing.

If you are not sure what format your audio file is, right-click it on your computer and look at the file extension (the letters after the dot). If it says .mp3, you have an MP3 file. If it says .wav, you have a WAV file. Most editors list their supported formats in the help documentation or in the import dialog itself, so you can check there if you are unsure.

Frequently Asked Questions

Can I add multiple audio tracks to the same video?

Yes. Most editors let you import as many audio files as you want, and they will all play at the same time. You control the volume of each one separately, so you can have background music, dialogue, and sound effects all playing together. Each audio file gets its own track in the timeline.

What if the audio is out of sync with the video?

Drag the audio clip left or right on the timeline to move it earlier or later. If the audio drifts out of sync partway through (which is rare but happens), you may have a frame rate mismatch between the video and audio files. Check your editor's documentation or try re-exporting the audio at the same frame rate as your video.

Can I remove the original audio from my video and replace it with new audio?

Yes. Right-click the original audio track and delete it, then import your new audio. The video will have only the new audio. If you want to keep both but make the original quieter, just lower its volume instead of deleting it.

Do I need special software to add audio, or can I use what I already have?

If you already have a video editor installed, it almost certainly has audio import built in. You do not need separate software. Free editors like DaVinci Resolve, CapCut, and OpenShot all handle audio the same way paid editors do.

What happens to the original audio file after I export?

Nothing. The original file stays on your computer unchanged. The editor makes a copy of the audio data and combines it with the video when you export. You can delete the original audio file after exporting if you want to free up space.