How to Merge Podcast Episodes into a Single File

To merge podcast episodes into a single file, open Zro7 Merge Audio, drop your files in order, and export. When every file uses the same codec, sample rate, and channel layout, Zro7 stream-copies them with FFmpeg's concat demuxer — no re-encoding, no quality loss, done in seconds even for hours of audio.

Fast path: concat demuxer (lossless)

If your episodes came from the same encoder (typical for one podcast feed), FFmpeg can bit-copy them end-to-end:

1. All files share codec (e.g. MP3 128 kbps), sample rate (44.1 kHz), and channels (stereo).
2. Zro7 writes a concat list and runs -f concat -c copy.
3. Output is a single MP3/M4A with the sum of all input durations. Zero quality loss.

Slow path: concat filter (re-encode)

Mixed formats (MP3 + WAV + M4A) need decoding to a common PCM stream before re-encoding. This is slower and lossy for MP3/AAC targets, but it always works. Zro7 switches to this automatically when your files don't match.

Steps

1. Open Merge Audio.
2. Drop files. Drag them in the sidebar to reorder.
3. Pick output format (matches the input by default).
4. Export. Download the single merged file.

Before merging: clean each episode

• Normalize to -16 LUFS so episodes don't jump in volume.
• Strip long silences from bad edits.
• Fade each episode's start/end for smooth transitions.