Join audio when you want two to ten browser-decodable files combined into one gap-free PCM16 WAV in a specific, continuous order. Here, “joining audio” means concatenating finished clips so one track ends and the next begins at the shared sample boundary; it does not mean mixing tracks at the same time or entering a live call. Audio Joiner fits that task because it decodes the selected files in the order shown, concatenates their channel samples directly, and creates a downloadable RIFF/WAVE file. The last sample frame of one track is followed immediately by the first sample frame of the next: no silence, overlap, crossfade, normalization, transition, or automatic trimming is inserted. The right moment to join is after the individual pieces are edited and you know their final sequence, but before delivery. Check first that every input has the same decoded channel count and that the selection fits the tool’s file, duration, sample-rate, channel, and sample budgets. Recognized MP3, WAV, M4A, AAC, Ogg, WebM, and FLAC names can be selected, although the current browser and operating system must be able to decode the actual codec. If you need only a time range, use Audio Cutter first. Use a dedicated editor when you need fades, loudness matching, channel conversion, compressed output, metadata preservation, or sample-level repair.
Decide Whether the Task Is a True Join
Use a join at the handoff point between editing separate clips and delivering one continuous file. The task fits when:
- Each clip is complete and should play from beginning to end.
- The sequence is known, and every clip should begin immediately after the previous one.
- You need one combined file instead of a group of separate tracks.
- All clips decode to the same channel count.
- The current browser can decode every file, and the selection meets every limit below.
A join is not a substitute for mixing or mastering. If clips need to overlap, play simultaneously, fade into one another, be loudness matched, change channel layout, remain compressed, retain metadata, or be repaired at sample level, use a dedicated editor. Audio Joiner intentionally performs none of those transformations.
Know What the Joined WAV Will Contain
Every file in a selection is decoded through one AudioContext. The browser’s decodeAudioData operation produces decoded channel data represented by an AudioBuffer. Because all files share one context, sources may be resampled to that context’s working sample rate. The rate shown for the tracks and result can therefore differ from rates stored in the original files; independent source sample rates are not preserved.
The download is newly encoded as RIFF/WAVE with interleaved, little-endian, signed 16-bit PCM samples. Matching channels retain their identity and decoded order, so a stereo left channel remains left and the right channel remains right. The output does not preserve the original codec, bitrate, encoder settings, tags, album art, chapters, cue points, loop points, loudness fields, timestamps, or other container metadata. It is a new static PCM representation, and because PCM WAV is uncompressed, it can be much larger than compressed MP3, AAC, Opus, Vorbis, or FLAC inputs.
Check Every Limit That Can Stop the Join
A recognized file extension is only a selection hint, not a guarantee that every codec variant will decode. Actual support depends on the codecs available in the current browser and operating system. The browser adds no codec library or server fallback, so damaged, encrypted, incomplete, mislabeled, or unsupported files produce a clear error instead of being processed by another system.
| Check | Limit or rule | What to verify |
|---|---|---|
| Number of files | 2–10 files | The selection contains at least two files and no more than ten. |
| Each encoded input file | 25 MiB (26,214,400 bytes) maximum | No individual source file exceeds the stated size. |
| Whole encoded selection | 100 MiB (104,857,600 bytes) maximum | The combined size of all selected files stays within the total limit. |
| Total decoded duration | 30 minutes maximum | The duration after decoding does not exceed the limit. |
| Channel layout | Up to 8 channels, with the same channel count required for every track | All clips are mono, all are stereo, or all share another compatible channel count. |
| Decoded working sample rate | Up to 192 kHz | The shared decoding context can handle the selected files within this rate. |
| Total decoded samples | 30 million samples counted across all channels | High-rate or multichannel selections do not exceed the overall channel-sample budget. |
Nothing is shortened, downmixed, downsampled, or omitted to force a selection into a limit; an invalid selection is rejected with a specific message. A high-rate or multichannel selection can reach the sample budget before the duration limit. A mixture of mono and stereo tracks is also rejected rather than silently duplicating, dropping, averaging, or remapping channels.
Build the Joined Track in the Intended Order
Once the files are compatible and the sequence is settled, follow this workflow:
- Choose the files together. Select 2–10 browser-decodable audio files within the displayed per-file and total input limits.
- Wait for decoding and preview the tracks. Confirm that each decoded track is the material you intended to combine and note its displayed rate.
- Set the sequence. Use Move up or Move down until the visible list is in the required order. The visible order and join order change together, and an older joined WAV is cleared after reordering so it cannot represent a stale sequence.
- Start the join. Select Join in this order. The tool concatenates the decoded channel samples directly, with no inserted silence, overlap, crossfade, normalization, transition, or automatic trimming.
- Preview the PCM16 WAV. Listen to the complete result and check the track order, boundaries, duration, and channel playback.
- Download the new WAV. Save the joined file locally, but retain the original sources until the downloaded result has passed your final checks.
Review the Download Before It Replaces the Sources
Use a final playback and file check before delivering or deleting anything:
- Confirm that every clip appears in the intended order.
- Check each join for unintended silence, overlap, or an abrupt transition.
- Verify the downloaded duration.
- Confirm that every channel plays as intended.
- Check that the file size is plausible for an uncompressed PCM WAV.
Confirm the downloaded duration, order, joins, channel playback, and file size before deleting any original. If the original tags, loudness fields, timestamps, or other container information matter, keep the source files because those properties are not carried into the joined WAV.
Choose a Different Workflow When the Goal Differs
| Goal | Recommended route | Why |
|---|---|---|
| Play complete clips one after another | Audio Joiner | It concatenates 2–10 files in the exact visible order and creates one gap-free PCM16 WAV. |
| Keep only an exact time range | Audio Cutter | Cut each required range first; join the resulting files afterward if several ranges still need one sequence. |
| Add fades, match loudness, convert channels, or repair samples | Dedicated editor | Audio Joiner performs none of these sample-level or mixing operations. |
| Deliver a compressed file or preserve container metadata | Dedicated editor | The joined output is a new PCM16 WAV without the original codec or metadata. |
| Combine simultaneous layers | Dedicated mixing workflow | A join places tracks sequentially and does not overlap or mix them. |
For a straightforward sequential file, join after the clips are final, the order is fixed, the channel layouts match, and the limits are satisfied. File reading, Web Audio decoding, channel concatenation, WAV encoding, preview, and download all happen in the current browser tab, so the source files are not uploaded.
Related reading: When Should I Join Audio Instead of Doing It Manually?.
Related reading: Why the Output WAV Can Be Larger Than the Sources.