Audio Joiner Online

A browser-based audio joiner with per-clip volume, trim, fade in/out, crossfade curves, EQ, and loudness normalization. Merge MP3, WAV, FLAC, OGG and 5 more formats — no limits.

How to Merge Audio Files

Upload Files

Drag and drop or browse to add 2 or more audio files. All common formats are supported.

Arrange & Edit

Drag tracks to reorder. Expand each track to adjust volume, trim, fade in/out, and EQ. Set a transition (crossfade or gap) between tracks — the duration is in seconds.

Preview

Click Play to hear the merged result in real-time before exporting. Seek to any position.

One track, with the loudness evened out

Choose your output format and quality, enable loudness normalization if your tracks differ in volume, click Join, and download the merged file.

Combine, trim, crossfade, and normalize multiple audio tracks into one

Upload audio files

📁

Drop a file here

Drop 2 or more audio files to merge them into one. Any length, up to {mb} MB in total.

MP3, WAV, OGG, FLAC, M4A, AAC, OPUS…

Add at least 2 audio files

Target:

Match loudness across all tracks to a consistent level

+ Add more audio

Format

Quality

Channels

Auto — same as the source files

Processing…

Processing canceled. You can start again when ready.

Process

What happens to quality when files are joined

Joining does not always mean re-encoding. Whether the audio is touched at all depends on what the files are and what you ask for.

Case	What happens
All files are MP3 with the same sample rate and channel count, and nothing else is applied	Frames are copied as they are — no decoding, no loss, and no bitrate ceiling to speak of, because nothing is encoded
A crossfade, a gap, trimming, volume, EQ, normalisation or a different output format	The audio is decoded and encoded again; the encoding quality follows your plan
Files differ in sample rate or channel count	Everything is brought to 48 kHz and one channel layout first, which means encoding

By our own telemetry, a bit over half of all joins are the first case: same files, nothing applied. If that is yours, the result is bit-for-bit the source.

What You Can Do

Per-Clip Editing

Trim start/end on the waveform, adjust volume 0–200%, set fade in/out up to 5 seconds, and fine-tune bass/treble EQ — all per track.

Smart Transitions

8 transition presets — Smooth Blend, DJ Crossfade, Echo Trail, Low Pass Sweep and more. 5 crossfade curves, custom duration, or full manual control.

Loudness Normalization

One-click LUFS-based loudness normalization. Match volume across all tracks to -14 (streaming), -16 (general), -19 (broadcast), or -23 (audiobook) LUFS.

Frequently Asked Questions

How do I stop the join between two clips from clicking?

A click at a seam is almost always two waveforms meeting mid-cycle, and there are three ways out. A short fade on each side is enough for speech. A crossfade blends the two, which is what you want when the second clip should feel like a continuation rather than a new file — eight presets cover the usual shapes, from a smooth blend to a DJ-style overlap. And if the levels differ, loudness normalisation across the whole set removes the other kind of seam, the one you hear as a jump rather than a click.

Can I merge files of different formats?

Yes. You can combine MP3 with WAV, FLAC with OGG, or any other combination. The tool automatically converts all tracks to a common format before merging.

What are crossfade curves?

Crossfade blends the end of one track into the start of the next. Linear fades at a constant rate. Equal Power maintains perceived loudness during the transition. Logarithmic creates a faster initial fade that slows down.

Does merging reduce audio quality?

Lossless formats (WAV, FLAC) preserve full quality. For lossy formats (MP3, OGG), you can choose bitrate up to 320 kbps. The tool resamples everything to 48 kHz stereo for consistent output.

What does normalization do, and when should I turn it on?

Normalization here is EBU R128 loudness matching: every track is brought to the same loudness target (−16 LUFS by default), so quiet and loud recordings end up at a consistent level. Enable it when your tracks come from different sources or were recorded at different volumes. If the tracks are already similar in loudness, the result will sound the same — that is the correct behavior. The result panel shows the measured LUFS of the exported file.

Which format should I pick: MP3, WAV, or something else?

MP3 at 192 kbps suits most uses and sharing; pick 320 kbps for higher quality. Choose WAV or FLAC (lossless) if you plan to edit the file further. "Channels: Auto" keeps the channel count of your source files.

What unit is the transition measured in, and what should I choose?

Crossfade duration is set in seconds. For music, 1–3 seconds is typical. The default equal-power curve keeps perceived loudness steady, so there is no volume dip in the middle of the transition.

Will my work survive if I close the tab?

Yes, if you save a draft. The “Save draft” button stores the tracks and every join setting in this browser, and you can come back to them within 30 days. A draft belongs to this browser only: it will not be there on another device or in another browser. Without a saved draft, closing the tab means assembling the join again from scratch.

💡 Want us to improve this tool just for you?

We can! Just send us a quick message with your idea. If you'd like to discuss it in detail, leave your email and we'll get back to you. You can stay anonymous.

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Who is this tool for?

Published 01 Feb 2026 Updated 10 Jun 2026 Author: The Supreme