Mix MP3 audio with crossfade (2025 guide)

Jump straight into the mixer: upload your clips, trim each segment with precise adjustment and apply crossfade for smooth transitions. Export everything as a single MP3. Works great with WhatsApp voice notes, interviews, and music playlists.

We add an audio and its timeline appears

When we load our audio, its track appears, allowing clip editing, trimming, and crossfade. You also get precise time controls via the dedicated button, plus the ability to preview the edited clip.

As you load more audios, new tracks appear so you can edit each one before mixing and exporting a single MP3

As more audios are loaded into the online mixer, new tracks are generated so you can edit each clip before mixing everything into a single MP3.

Precise trim adjustment

The online audio mixer offers a precise adjustment dialog with ±0.1 and ±0.01 controls.

How to mix (step by step)

1. Open the audio mixer.
2. Upload your files (MP3, M4A, OGG, OPUS, AMR, WAV…). You can drag & drop.
3. On each track, select the segment and use Preview trim to check it.
4. For maximum accuracy, click Precise adjustment and set start/end times to the millisecond.
5. Add a crossfade in seconds into the next track (smooth transition).
6. Click Preview to listen to the mix and tweak as needed.
7. Click Download final MP3 to get the finished file.

Workflow & crossfade tips

• WhatsApp → MP3 → Mix: if your notes aren’t MP3 yet, convert them here: WhatsApp to MP3.
• Voice: 0.5–2.0 s of crossfade usually feels natural.
• Music: try 2–5 s and align to the tempo to avoid harsh cuts.
• Stable volume: if any clip is too loud/quiet, go back and normalize it with the MP3 → MP3 converter.

Related

• WhatsApp → MP3
• Trim audio (MP3)

Frequently asked questions