Audio Merger

Merge multiple audio files in your browser. Trim segments, fade in/out, add crossfades, preview, and export to WAV.

Drop audio files here or

Add at least two tracks (MP3, WAV, OGG, M4A, etc). All processing happens in your browser.

Project Sample Rate (Hz)

Tip: Keep 44100 for maximum compatibility.

Default Crossfade (seconds)

Automatically overlaps consecutive tracks.

Headroom Gain (dB)

Reduces peak clipping when overlaps occur.

Audio Preview

0:00.000 0:00.000

Click anywhere on the waveform to jump to that position • Hover to see play/pause control

FAQ & Implementation Notes

Fades & Crossfades: Each track supports its own fade in/out. The global crossfade overlaps consecutive tracks by your chosen duration while also applying their fades.
Trimming: Set Start and End (in seconds) to slice a smaller segment from each source before mixing.
Preview: Real-time scheduling with Web Audio API.
Export: Rendered with OfflineAudioContext and saved as WAV (lossless).
Privacy: Files never leave your device.

Open-source acknowledgements

About the Audio Merger

Audio Merger stitches multiple audio files into a single lossless WAV — sequencing tracks back-to-back, trimming each one, applying per-track fade in/out, and optionally crossfading between consecutive clips. Drop two or more files, arrange the order, fine-tune the timing, preview the result on a live waveform, then render the final mix.

Everything happens inside your browser using the Web Audio API and OfflineAudioContext. Your files are never uploaded, never queued on a server, and never logged. Close the tab and they're gone — safe for unreleased music, voice memos, client work, or anything else you'd rather not hand to a third party.

What you can control

Multi-format input: MP3, WAV, OGG, M4A, and anything else the browser can decode — mix formats freely in one project.
Project sample rate: Default 44,100 Hz for maximum compatibility. Bump up to 48,000 / 96,000 Hz for higher-fidelity work.
Per-track trim: Set precise start and end times in seconds to slice each source down to the segment you want before mixing.
Per-track fade in / fade out: Smooth the head and tail of each clip individually.
Default crossfade: Set a single number and consecutive tracks automatically overlap by that duration — great for seamless playlists or DJ-style mixes.
Headroom gain (dB): Pull peaks down (default −1.0 dB) to prevent clipping when overlapping tracks stack up.
Reorder tracks: Use the arrow keys or buttons to shuffle the running order without re-uploading.
Waveform preview: Scrubbable visual playhead — click anywhere on the waveform to jump to that position before you commit to a render.
Lossless WAV export: The final render is a high-quality, uncompressed WAV file.

Common uses

Combining voice memos or interview takes into a single edited file.
Building seamless podcast episodes from intro, segments, ads, and outro clips.
Stitching together music demos and stems for sharing or further mixing.
Creating crossfaded playlists or workout mixes from individual songs.
Joining audiobook chapters, language-lesson recordings, or meditation tracks.
Merging multi-take voiceovers for video projects before laying them over picture.

Tips for the best results

Set every track's fade in/out to 0.05–0.1s as a safety net to avoid pops at the join points, even without a full crossfade.
For musical mixes, try a global crossfade of 2–4 seconds. For spoken word, 0.1–0.3s usually feels right.
Keep headroom around −1.0 to −3.0 dB if you're crossfading loud material — overlapping peaks can clip otherwise.
Stick to 44,100 Hz unless you have a specific reason. Most distribution platforms expect 44.1 or 48 kHz.
Preview the full mix before rendering — the waveform reflects every fade, trim, and crossfade exactly as it'll export.
Trim leading silence from each source with the Start input. It's faster than re-encoding the files elsewhere.

No accounts, no upload queue, no length limits — drop your audio, arrange the order, and render. The final WAV is yours to compress, distribute, or mix further in any DAW.