How to Reduce Audio File Size Without Losing Quality

Large audio files — especially uncompressed WAV and FLAC — can be impractical to share, store on mobile, or upload to podcast hosts. Here are the best strategies depending on your source format.

Strategy 1: Convert WAV or AIFF to FLAC (Lossless Size Reduction)

If you have an uncompressed WAV file, FLAC reduces file size by 40–60% with zero quality loss:

Using Audacity:

1. Open your WAV in Audacity
2. File → Export → Export as FLAC
3. Choose bit depth: 16-bit (for CD-quality sources) or 24-bit (for studio-quality sources)

A 100 MB WAV file typically becomes 40–60 MB as FLAC with no audible difference.

Strategy 2: Convert WAV/FLAC to AAC or MP3 (Lossy, Maximum Compression)

For maximum size reduction (90%+), convert to a high-quality lossy format:

Recommended settings:

• Podcast/speech: AAC 96 kbps or MP3 128 kbps — indistinguishable for voice
• Music streaming: AAC 256 kbps or MP3 320 kbps — transparent to most listeners
• Mobile storage: AAC 192 kbps — excellent balance of size and quality

Strategy 3: Reduce Sample Rate for Speech Content

If you have a 48 kHz or 96 kHz audio file containing only speech (podcasts, audiobooks, voiceovers):

• Converting to 44.1 kHz loses no perceptible quality for speech
• Converting to 22 kHz (telephone quality) is acceptable for voice-only content

In Audacity:

1. Open your audio file
2. Tracks → Resample → set to 44100 Hz
3. Export in your target format

Strategy 4: Trim Silence and Dead Air

Cut silent intros, outros, and gaps:

1. Open in Audacity
2. Effect → Truncate Silence — automatically removes silence below a threshold
3. Manually trim start/end silence with the Selection Tool

File Size Reference (4-minute audio, stereo)