How to Mix Multiple Audio Tracks into a Video or Merge Audio Files Online

Last Updated: Feb. 08, 2022

Audio mixing in a video refers to balancing, editing, and combing all the audio files recorded for a video.

Mixing multiple audio tracks into a video is a crucial step in post-production. It works esp. when your videos or video podcasts involve multiple audios, such as ambient sounds, different speakers’ voices, and the background music and sound effects.

In this post, we will introduce you to some easy-to-use audio mixers online. So, you can easily mix two or multiple audios into a video in minutes or merge multiple audio files into an MP3 or WAV, etc.

Here’s What You Will Learn:

How to Mix Multiple Audio Tracks into a video by FlexClip

If you have recorded different speakers’ voices for a video podcast or need to combine audio files like background music, sound effects, or your voiceovers into a video and make some edits, a great tool we recommend is FlexClip, a free and versatile video maker and audio mixer online.

FlexClip online video editor and audio mixer

FlexClip online video editor and audio mixer

Best Features for Mixing Audio and Video:

  • Mix multiple audio tracks into one video.
  • Add fade in/out effects for audio; mute, split, and trim audio; adjust audio volume.
  • Easily do J Cut or L Cut of your audio in two video scenes using the intuitive timeline.
  • 4M+ royalty-free stock assets, including videos, images, GIFs, and thousands of music and sound effects.
  • Tons of video tools like video filters, transitions, picture-in-picture feature, speed control, etc. take your video and audio to the next level.
  • Easy for share: local download; cloud storage; share to YouTube, Dropbox, Google Drive; generate clickable link and embed code.
  • Step 1: Upload Video and Audio to FlexClip

    After you upload videos and audio to FlexClip, click the “+” icon to add them to the timeline.

    Upload videos and audio files to FlexClip and add them to the timeline

    Upload videos and audio files to FlexClip and add them to the timeline

    Step 2: Mix and Edit Multiple Audio

  • Drag and drop the audio slider to trim the audio track.
  • Use the split tool to remove the unwanted noise or mute the audio completely.
  • Add fade in/out effect to create a smooth transition between two audio.
  • Drag one audio track over another to create the overlapping audio, known as J Cut or L Cut.
  • Click the “Music tab” on the left sidebar to add a royalty-free background of sound effects when needed.
  • mix and edit multiple audio

    Use tools to trim, split audio tracks or add fade effects or royalty-free music or sound effects

    Step 3: Preview, Export, and Share

    Click the “Export” button on the top right corner. You can directly download the MP4 video with mixed audio to the local pc. Or share it with your friends for feedback with a clickable link or use the embed code for your blogging. You can also directly share it to YouTube or save it in Dropbox, and Google Drive.

    Export and share the video in multiple ways

    Export and share the video in multiple ways

    Who is FlexClip Best-suited For?

    For Vloggers, YouTubers, video podcasters, etc, FlexClip can offer you a hassle-free experience to mix audio tracks into a video in minutes. The vast royalty-free stock assets will be a huge bonus for your audio video mix.

    2 Other Free Audio Mixers Online to Combine Audio Files

    If all you need is to mix audio tracks online like combing a piece of music with your vocal and keep it as a merged audio file for the audio podcast or music production, then the 2 following online free audio mixers should serve you well.

    1. Online Converter

    Online Converter is a free audio mixer online that is capable of mixing up to 4 audio tracks into one in your browser and without any registration. Some of the audio formats it supports are MP3, WAV, OGG, M4A, and WMA. The only downside is that you can’t preview your new audio in real-time and features are so limited.

    Mix multiple audio tracks by Online Converter audio mixer

    Mix multiple audio tracks by Online Converter audio mixer

    Best Features for Mixing Multiple Audio:

  • Support up to 10 audio formats for audio mixing: MP3, OGG, MIDI, M4A, WMA, AMR, FLAC, ALAC, AIFF, WAV, and more
  • Set duration and transition for mixing audio
  • Easy share to Facebook, Twitter, Reddit, E-mail, Pinterest, Linkedin or your mobile phone
  • No registration required
  • Step 1: Upload Audio Files to Online Converter

    Step 2: Set the Duration and Transition of Mixed Audio File

    Step 3: Click the “Mix” Button to Combine Audio Files and Download or Share

    Who is Online Converter Best-suited For?

    If you are satisfied with the original audio files and no more editing is needed, then you can use Online Converter to mix audio tracks in seconds.

    2. Audio Joiner

    Audio Joiner is a user-friendly audio mixer online made solely for audio mixing. Its minimal interface allows you to easily upload multiple audio files, then do the trimming and add fade in/out effect and combine all the audio files for download and share to Clouds.

    Use Audio Joiner to mix multiple audio online for free

    Use Audio Joiner to mix multiple audio online for free

    Best Features for Mix Multiple Audio:

  • Easy-to-use and minimal interface.
  • Support more than 300 audio formats.
  • Unlimited audio tracks for uploading and mixing. Awesome!
  • Trim each audio track, adjust audio position, add crossfade effect.
  • Mix audio files and Export as MP3, M4A, WAV, FLAC.
  • Local download, or share to Dropbox and Google Drive.
  • Step 1: Upload Audio Files to Audio Joiner

    Step 2: Edit the Audio Files

    You can trim audio files, add fade-in, crossfade effect, or drag audio sliders to set an interval between each audio.

    Step 3: Select Audio Format for Download and Share

    Who is Audio Joiner Best-suited For?

    With unlimited audio tracks for mixing and supporting more than 300 audio formats, Audio Joiner is a sweet and nifty online audio mixer for pure audio mixing. Vocalists, podcasters will love using Audio Joiner to mix audio for high-quality audio files.

    Now, It's Your Move

    No audio mixer is made equal. Hopefully, you will find our recommended tools helpful. If you need to mix multiple audio tracks into a video, the versatility and huge royalty-free stock assets of FlexClip is the best choice. While the rest 2 audio joiners will meet our different needs. So, start combing audio files, now!

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