Audio Joiner & Merger
Merge multiple audio files, songs, and voice notes into one track with custom crossfade transitions locally. Your files are never uploaded to our servers. ToolkitPoint processes them on your own computer, so confidential documents stay with you.
Processed in your browser. Your files are not uploaded.
How to use Audio Joiner & Merger
- Click "Add Audio Tracks (Multi-Select)" and select two or more files (MP3, WAV, OGG, M4A, FLAC or AAC); each appears as a card with length, sample rate and channel count.
- Reorder the playlist with the ▲ and ▼ buttons, delete a card with ✕, and set each card's "Vol:" slider between 0 and 2.
- Set the crossfade (0 to 5 seconds) and its curve, or set a crossfade of 0 and add a silence gap. Optionally match loudness to the average of the tracks, -16 LUFS or -14 LUFS.
- Choose the output: WAV, MP3, M4A, OGG, FLAC, or a lossless join for same-format MP3 or M4A files (no re-encode), plus the sample rate.
- Press "Merge Audio Tracks", listen to the result, then download it. Copy or download the chapter list (text or CUE) with each track's start time.
Worked example
Load intro.wav (30 s) then song.mp3 (200 s), leave the crossfade at 1.5 s, choose MP3 and match loudness to -16 LUFS. The merged file is 228.5 seconds (3:48) and the chapter list reads 00:00 intro, 00:28 song.
When to use this tool
- Stitching separately recorded podcast segments into one episode file.
- Blending several song clips into a continuous mix with smooth overlaps.
- Adding a jingle before a voice recording and lowering its volume slider.
Important limitations
Tracks are decoded into memory, so very long or many files can exhaust a device (about 250 MB total is a sensible ceiling); the lossless join path avoids decoding for the audio data. MP3/M4A/OGG/FLAC export uses FFmpeg on your computer and downloads about 32 MB of engine code the first time.
Comparing alternatives
Other options for audio joiner & merger include AudioJoiner (123apps), Clideo, Bear Audio, Aconvert.
ToolkitPoint is not affiliated with those services.
Frequently asked questions
How is the merged length worked out?
Durations are added together, then each junction subtracts its crossfade (or adds your silence gap when the crossfade is 0). Three tracks of 30, 20 and 25 seconds with a 1.5 second crossfade give 75 - 3 = 72 seconds.
Can the crossfade be longer than the tracks allow?
The overlap at every junction is capped at half the length of the shorter neighbouring track. A 3-second clip therefore never overlaps by more than 1.5 seconds, whatever the slider says.
What does loudness matching do?
Each track's integrated loudness is measured (ITU-R BS.1770 gated LUFS) and gained toward the average or a -16/-14 LUFS target, so a quiet track no longer sits far below a loud one. Where a boost would push a peak past -0.5 dBFS it is limited, and the table under the player shows the measured LUFS, peak and gain per track. Sample peak, not true peak, is reported.
When can I join without re-encoding?
When every file is an MP3 (or every file is an M4A) with matching encoder settings, and crossfade, gap, loudness matching and volumes are all left neutral. The audio data is copied as it is, so quality is unchanged. If the files differ, the page asks you to pick a re-encoded format.
Which sample rate does the output use?
You choose 44.1 kHz or 48 kHz. Every track is decoded at that rate by the browser before mixing.
What is the chapter list?
It lists each track's start time (after crossfades or gaps), such as 00:00 Intro, 03:12 Song. Copy it into a YouTube or podcast description, edit the titles, or download a .cue sheet.