Convert whole batches of audio between WAV, MP3, and OGG with one output format and sample rate for the whole batch. Podcasters standardize 50 episodes for every platform — local processing, 2 free batches a day.
Runs on FFmpeg
Content reviewed October 2026 · About Toolzum
Convert your MP3 music library to lossless WAV format in one batch. Audio editors and podcasters need WAV for professional production workflows. Everything runs locally in your browser — nothing is uploaded.
Level whole audio batches with peak normalization to a target dBFS level (default -3) without crushing dynamics. Networks even out 30 episodes so listeners stop riding volume — local Web Audio work, 2 free batches a day.
Batch compress WAV recordings to space-saving MP3 files. Podcasters shrinking raw studio recordings for distribution on Spotify and Apple Podcasts. Everything runs locally in your browser — nothing is uploaded.
Detect and blur or pixelate faces across whole photo batches with on-device BlazeFace (one shared model download for the batch). Faces need confidence above 0.5 and size above 8px; faceless files are skipped with an error. Outputs PNG as <name>-anonymized.png — local processing, 2 free batches a day.
Burn one shared SRT subtitle file permanently into a whole batch of videos with font-size and bottom/top/middle position control. Course creators hard-sub 20 lessons for platforms that ignore caption files — FFmpeg WASM, 2 free batches a day.
WAV 44.1 kHz for editing masters, MP3 for Spotify and RSS feeds, OGG as the open alternative. Set once per batch: sample rates run 8, 22.05, 44.1, or 48 kHz — WAV output needs no engine while MP3/OGG transcode through FFmpeg.
FFmpeg WASM processes sequentially in your browser: short clips finish in seconds each, hour-long WAVs take minutes. A 50-episode MP3 batch typically completes in 10–20 minutes on a laptop — start it, keep the tab open, and download the ZIP once.
No — conversion preserves at best and degrades at worst, especially lossy-to-lossy. Fix noise and levels in the WAV masters first, then convert outward. Never upconvert MP3 to FLAC expecting quality gains; the file grows with zero fidelity added.
No — conversion runs locally in your browser with FFmpeg WASM; audio never leaves your device. Only the final ZIP save counts as one Pro download (signed-in free: 2 a day; Pro unlimited).
Audio Format Converter
Convert between MP3, WAV, FLAC, OGG, M4A, and AAC audio formats. Pick any input and output format — your files never leave your device.
Bulk MP3 to WAV
Convert your MP3 music library to lossless WAV format in one batch. Audio editors and podcasters need WAV for professional production workflows. Everything runs locally in your browser — nothing is uploaded.