Stereo to Mono Audio Converter — Free Online

Convert stereo audio to mono by averaging both channels. Fully browser-based.

ファイルは約1時間後に削除されます

Stereo audio is not always what you need. Podcast voice tracks, telephone system prompts, voice assistants, and many web applications all use mono audio to reduce file size and ensure consistent playback across all speaker configurations. Converting stereo to mono is also a standard step before noise reduction or pitch analysis, since many algorithms expect a single-channel input.

This tool converts stereo audio to mono by averaging the left and right channels, producing a centre-panned result that preserves the full frequency content of both channels. It is fast, lossless in terms of frequency content, and outputs a mono file at the original sample rate and bit depth.

How to Convert Stereo Audio to Mono Online

  1. 1

    Upload your stereo audio file

    Drop any MP3, WAV, FLAC, OGG, or AAC stereo file. Files up to 100 MB are supported.

  2. 2

    Confirm the conversion

    FileCrank mixes both channels into a single mono channel by averaging left and right.

  3. 3

    Download your mono audio

    Click Convert. Your mono file is ready to download. Files are deleted within 1 hour.

How Stereo-to-Mono Down-mixing Works

Down-mixing stereo to mono involves combining two channels into one. The standard approach is to average the left and right channel samples: mono[n] = (left[n] + right[n]) / 2. This preserves all content that was panned to centre while retaining contributions from both channels. Content panned hard to one side will be at half amplitude in the mono output, which is perceptually a 6 dB reduction.

An alternative approach — used for maximum mono compatibility — applies equal-power (−3 dB) scaling to each channel before summing, so that a signal panned centre maintains the same loudness in mono as in stereo. The tool uses FFmpeg's amerge and pan filters running in WebAssembly to perform the mix, and optionally applies a peak limiter to prevent clipping when loud stereo content combines.

Why Use FileCrank to Convert to Mono?

  • ✓ Averages left and right channels for a balanced mono mix.
  • ✓ Supports MP3, WAV, FLAC, OGG, and AAC input.
  • ✓ Reduces file size by roughly half compared to stereo.
  • ✓ No watermarks, no signup, completely free.
  • ✓ Files are processed securely and deleted within 1 hour.

機能と仕様

最大ファイルサイズ
最大100 MB
プライバシー
ファイルは約1時間後に削除されます
料金
無料、登録不要
処理方式
サーバーサイド
ファイルは1時間以内に自動削除されます。登録不要。無料 — 隠れた料金なし。

Frequently Asked Questions

Why convert stereo to mono?

Mono audio is smaller and works better for podcasts, voice recordings, and phone calls where stereo adds no benefit.

Will I lose any audio content?

Both channels are averaged so no content is lost, but any stereo spatial effect (panning, width) is removed.

What formats are supported?

MP3, WAV, FLAC, OGG, and AAC input files are supported.

Down-mix Tool vs Manual Mixdown in a DAW

In a DAW, converting stereo to mono involves creating a mono master bus, routing the stereo track to it, and bouncing the result — several steps for what is a trivial operation. This tool converts in a single click, in the browser, and handles the channel arithmetic correctly without any manual routing configuration.

FileCrank Stereo to Mono Converter mixes stereo audio down to a single mono channel by averaging both channels. Supports MP3, WAV, FLAC, OGG, and AAC. Free, no signup, files deleted within 1 hour.

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