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オーディオコンバーター

MP3、WAV、FLAC、AAC、OGG、Opus間でオーディオファイルを変換 — ブラウザ内のFFmpegで動作、100%%プライベート

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Audio Converter — Free Online Format Converter

Convert audio files between MP3, WAV, OGG, M4A, FLAC, and WebM formats — entirely in your browser using FFmpeg WebAssembly. No upload needed, your files stay on your device.

FAQ

What audio formats are supported?

Input: MP3, WAV, OGG, M4A, AAC, FLAC, WebM, and more. Output: MP3, WAV, OGG, M4A, FLAC. The tool uses FFmpeg which supports virtually all audio codecs.

Is my audio uploaded to a server?

No — all conversion happens locally in your browser using FFmpeg compiled to WebAssembly. Your audio files never leave your device.

What is the difference between lossy and lossless formats?

Lossy formats (MP3, OGG, AAC) compress audio by discarding inaudible data — smaller files but some quality loss. Lossless formats (WAV, FLAC) preserve all audio data — larger files but perfect quality.

What bitrate should I use for MP3?

128 kbps for speech/podcasts, 192 kbps for casual music listening, 256–320 kbps for high-quality music. Higher bitrate = better quality but larger file size.

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