How to use Audio Joiner
Merge multiple audio clips into one seamless track entirely in your browser using the Web Audio API — no uploads, no server processing, no registration required. Add MP3, WAV, OGG, AAC, or FLAC files in any order, arrange them by dragging, then export the joined result as a high-quality WAV file. Perfect for assembling podcast segments, combining music loops, or stitching field recordings into a single deliverable.
- Click "Add audio files" or drag and drop your clips onto the upload zone.
- Reorder the clips by dragging them into the sequence you want.
- Optionally trim the start or end of each clip using the per-clip controls.
- Click "Join" — the Web Audio API decodes each file, resamples to a common sample rate, and concatenates the audio buffers.
- Preview the joined audio, then click "Download WAV" to save the result.
Your data never leaves your device — 100% private processing.
How browser-based audio joining works
The Web Audio API's AudioContext.decodeAudioData() method decodes each input file into a raw PCM AudioBuffer regardless of the source codec. The tool then reads the sampleRate of every buffer and resamples any that differ from the target rate (typically 44 100 Hz or 48 000 Hz) before writing sequential sample frames into a single output buffer. The result is encoded to WAV (PCM 16-bit little-endian) using a JavaScript encoder and handed to the browser for download — all without touching a server.
| Format | Container | Browser decode | Notes |
|---|---|---|---|
| MP3 | .mp3 | All modern browsers | Lossy; most common source format |
| WAV | .wav | All modern browsers | Lossless PCM; largest file size |
| OGG Vorbis | .ogg | Chrome, Firefox, Edge | Lossy; not supported in Safari |
| AAC / M4A | .m4a, .aac | All modern browsers | Lossy; native on Apple devices |
| FLAC | .flac | Chrome, Firefox, Edge | Lossless; not decoded in all Safari versions |
Sample-rate matching and audio quality
Every digital audio file has a sample rate — the number of audio samples captured per second (e.g. 44 100 Hz for CD audio, 48 000 Hz for video production). When joining clips recorded at different sample rates, you must resample them to a common rate before concatenation. Mismatched rates cause the pitch and speed of some clips to sound wrong. The Web Audio API handles resampling internally via its AudioContext target sample rate. For the best output quality, use source files recorded at the same sample rate and avoid repeatedly re-encoding lossy files.
Exporting as WAV and converting further
The joined file is exported as uncompressed PCM WAV, which preserves full audio fidelity and is universally compatible. WAV files are larger than MP3 or AAC equivalents, so if file size matters, pass the downloaded WAV through an audio converter to re-encode it as MP3 or AAC. For video production workflows, 48 000 Hz stereo WAV is the standard interchange format accepted by every major video editor and DAW.
Worked examples
Three podcast segments
Inputs: Clips of 3:00 + 4:00 + 3:30
Result: 10:30 WAV
Intro + interview + outro
Inputs: 0:10 + 25:00 + 0:20
Result: 25:30 WAV
Glossary
- AudioBuffer
- An in-memory object in the Web Audio API holding decoded PCM audio samples as floating-point arrays, one array per channel.
- Sample rate
- The number of audio samples captured per second, measured in Hz. CD audio uses 44 100 Hz; video production typically uses 48 000 Hz.
- PCM
- Pulse-Code Modulation — the standard uncompressed digital audio representation where each sample is a numeric amplitude value.
- Resampling
- Converting audio from one sample rate to another by interpolating or decimating samples to match the target rate without changing pitch.
- Channel
- A single audio signal stream; stereo audio has two channels (left and right), mono has one.
Related reading
Frequently Asked Questions
Why use Audio Joiner?
- Accepts mixed source formats — MP3, WAV, FLAC, OGG and AAC — in the same batch
- Drag-to-reorder interface lets you arrange segments before committing to the join
- Automatically resamples clips to a common rate to prevent pitch or speed mismatches
- Exports uncompressed 16-bit PCM WAV for lossless output compatible with every DAW
Common use cases
- Join three recorded podcast segments into one continuous episode before publishing
- Concatenate a series of music loops into a longer background track for a game level
- Stitch multiple field recordings of bird calls into one archive file for a documentary
- Assemble separate chapter audio files from an audiobook narration session into one WAV
- Combine an intro jingle, a main interview recording and an outro bumper into one file
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