What This Is.

an all-in-one audio tool that runs ffmpeg in your browser tab. drop any audio or video file, then pick an operation from the tabs — convert, trim, filters, channel mix, metadata, merge, or custom command. nothing uploads.

Convert.

pick an output format — mp3, wav, m4a (aac), ogg (vorbis), opus, or flac. choose a target bitrate (64k–320k) and channel mode (mono, stereo, or keep original). works with any input ffmpeg supports, including video files (video stream stripped).

Trim.

set start and end timestamps (HH:MM:SS, MM:SS, or raw seconds) and get a trimmed clip. add multiple segments to export several clips from one file — each segment downloads separately with an optional label and track number metadata.

stream-copy is used when possible (mp3, wav, flac, ogg) for instant trims. other formats re-encode to mp3.

Filters.

volume adjustment. boost or attenuate by up to ±20 dB.
noise removal. ffmpeg's afftdn filter with configurable noise reduction (dB) and noise floor (Hz). good for removing background hum or room tone from voice recordings.
custom filter chain. any valid ffmpeg audio filter syntax. equalizer, compressor, limiter, highpass, lowpass — anything the -af flag accepts.

filters are also applied when converting or trimming if you've set them before switching tabs.

Mix Channels.

for stereo or multi-channel files: adjust the volume of each audio channel independently. preview the mix live in your browser via the Web Audio API (the sliders respond in real-time), then export with the levels baked into a stereo mp3 via ffmpeg's pan filter.

use case: a field recorder captured an interview with mic 1 on the left and mic 2 on the right. one speaker is too quiet. boost their channel, lower the other, export.

Metadata.

edit title, artist, album, genre, year, and track number without re-encoding — the audio data is copied as-is (codec copy). add arbitrary custom metadata fields for anything the standard tags don't cover.

Merge.

concatenate multiple audio files into one. add files, reorder them with the arrow buttons, then merge. uses ffmpeg's concat demuxer. the output is re-encoded to mp3 to handle mixed input formats cleanly.

Custom Command.

for power users: type any ffmpeg arguments directly. your input file(s) are available in the virtual filesystem. use $input for the first file or $input[N] for the Nth. the last argument is treated as the output filename.

Privacy.

nothing uploads. the audio stays in your browser tab. ffmpeg runs as WebAssembly — the same engine that powers video editors and media servers, compiled to run in a sandboxed browser environment. when you close the tab, everything is gone.

Limits.

max file size: 1 GB (limited by browser memory).
first load downloads the ffmpeg core (~32 MB). cached by the browser after that.
processing speed depends on file length and your device. a 5-minute file typically processes in a few seconds on a modern machine.
the wasm build of ffmpeg supports most common codecs but not hardware acceleration or some niche formats.