📖 Tool Introduction

Audio Merger is a completely free online concatenation tool that joins several independent audio files end to end in the order you choose, producing one complete long recording. You can multi-select files in one go or drop them in batches, and each item lands in the queue with its file name and duration, plus up-move, down-move and delete buttons nearby, so you can reorder or drop unwanted clips at any time. When you press Merge and export WAV, the program first decodes every clip into raw samples and then automatically resolves format differences: it takes the first clip's sample rate as the reference and linearly resamples the others to match, then targets the largest channel count among all clips by duplicating mono onto both tracks and aligning multi-channel tracks as needed. Finally it writes every sample back to back in queue order into a new buffer and exports an uncompressed WAV with a 44-byte standard header and little-endian PCM16. The merge needs no professional editor and no matching formats — mixing MP3, WAV and M4A files works correctly. It is ideal for stitching several interview recordings into one complete interview, chaining sound effects into a ringtone sequence, joining scattered screen-cast narration into a single voice track, or combining short course clips into one long file. Every decoding, resampling and concatenation step runs locally in the browser; the audio bytes never leave your device and are never uploaded to any server. The queue is deliberately lightweight: each row shows the file name and its duration, and the up, down and remove buttons let you shape the final result before any rendering happens, so a wrong order or an unwanted clip can be corrected instantly. When pieces come from different sources — a phone recording in mono, a stereo mix, a low-rate voice memo — the tool aligns them automatically instead of refusing the job, which is what makes mixing unrelated files practical for everyday users.

✨ Key Features

• Multi-file queue: add files by multi-select or in batches; order is clear at a glance
• Reorder freely: move each clip up or down, or remove it entirely
• Automatic resampling: linear interpolation unifies all rates to the first clip's rate
• Channel unification: mono duplicated onto both tracks; multi-channel aligned to the max
• Standard WAV export: 44-byte header, PCM16, wide compatibility
• Local processing: decoding and concatenation never touch the network, zero uploads

📝 How to Use

1. Click the dashed area to multi-select audio, or drop files in batches
2. Use up and down buttons to set the order, and ✕ to remove extra clips
3. Make sure at least two clips are in the queue, then press Merge and export WAV
4. Wait while decoding and concatenation finish; the merged WAV downloads automatically
5. The page shows the number of clips, total duration, channels and sample rate

⚠️ Notes

• At least two clips: merging needs two or more items in the queue
• Sample-rate differences: resampling may cause a very slight, usually imperceptible change
• WAV size: concatenated WAV files are large; watch disk space for long clips
• Order decides the result: the queue order is the final concatenation order
• Decode failures: files that cannot be decoded are skipped with a notice