ConvertBox Logo
ConvertBox

Audio Joiner

Merge multiple audio files into one track. Reorder clips, add silence between them, supports MP3/WAV/FLAC/AAC — all processed locally in your browser.

How to Use

  1. Select the audio files to join (2 or more)
  2. Adjust the order using the ↑↓ buttons
  3. Add more files using the "+ Add More Audio" button
  4. Click the "Join Audio" button
  5. The joined audio will be downloaded in MP3 format

All processing is done in your browser, and files are never sent to a server.

Frequently Asked Questions

You can join 2 or more audio files. There is no strict upper limit.
No, you can mix different audio formats. The output will be in MP3 format.
Yes, use the up and down buttons to reorder files before joining.
If joining fails: (1) use fewer or smaller files (total under 200MB), (2) ensure all files are valid audio formats, (3) refresh the page and retry. The output is always in MP3 format.
No. All operations are processed entirely inside your browser's local sandbox using client-side APIs (like WebAssembly, pdf-lib, or HTML5 Canvas). Your files and data never leave your device.
The tool is completely free with no usage limits. However, since processing occurs in your browser's memory, we recommend keeping file sizes under 50MB (especially for heavy files like PDFs or videos) to ensure stability.
No. All tools on ConvertBox are 100% free. We do not insert watermarks, limit features, or require any registration or payment.
Yes. Once the page and its local library dependencies are loaded in your browser, the conversion logic runs completely offline without needing an active internet connection.

Related tools

Convert Audio

Convert audio between MP3, WAV, FLAC, AAC, M4A and OGG. Choose bitrate, mono/stereo and sample rate, up to 100MB per file — all in your browser.

MP3WAVAAC
Get Started

Cut Audio

Trim audio files to extract a specific clip. Set start and end time to the millisecond, supports MP3/WAV/FLAC/AAC up to 100MB — processed locally.

MP3WAVAAC
Get Started

Compress Audio

Compress MP3, WAV, FLAC, and AAC audio in your browser. Adjust bitrate to shrink size while preserving sound — files up to 100MB, no uploads required.

MP3WAVAAC
Get Started

Adjust Volume

Adjust audio volume from -20dB to +20dB without re-encoding loss. Supports MP3/WAV/FLAC/AAC up to 100MB, processed locally in your browser.

Get Started

Video → Audio

Extract audio from MP4, MOV, WebM and AVI videos. Save as MP3, WAV, AAC or FLAC, pick bitrate and trim — processed locally with FFmpeg.wasm.

Get Started
NEW

Audio to Text

Use your browser's speech recognition to convert audio or video into SRT, VTT, or plain text. Real-time, private, free.

Speech → Text
Get Started