FLAC to AAC Converter

FLAC already halves a WAV without losing a sample, which means the decode step reads a compressed stream and the encode step writes a new codec from identical PCM. Free Lossless Audio Codec (FLAC) is a lossless audio format used for archiving music without sacrificing cd-quality data. Files saved as FLAC usually come from Xiph.Org. Before converting, check that the source is the highest-quality copy you have, because every later step can only preserve what is already there.

The target is Advanced Audio Coding (AAC), a lossy audio format chosen for efficient audio in mp4. The target uses perceptual lossy compression, which is efficient for playback but discards inaudible detail the encoder considers expendable. The output keeps the original dimensions or sample rate unless you change them, so this step changes the encoding rather than the content.

Raw AAC/ADTS keeps the efficient AAC codec but drops MP4 metadata and chapter support. It is convenient for streaming pipelines that expect elementary audio streams. Channel layout is preserved, so a stereo source stays stereo and a mono recording is not upmixed. The sample rate is preserved unless you change it; resampling would add another processing step and is best avoided. Expect a smaller output file, which is usually the reason to pick AAC.

This conversion runs locally in your browser tab through Canvas or FFmpeg.wasm. The file is read from your device, decoded, re-encoded and handed back as a download; it is not uploaded to a conversion server. That keeps private recordings, client material and unreleased artwork off shared infrastructure.

After the download, play or open the result before deleting the original. Check the first and last seconds, confirm that transparency, rotation metadata or sample rate survived, and compare file sizes. If something looks wrong, retry with a higher quality setting rather than converting the output again.