Convert MOV video to MP3 for free — pick the range and create it in your browser, no upload.
For an MP3 only the MOV's audio matters: Nerulio discards the video without decoding it, so HEVC and even ProRes MOVs work as long as the audio track can be decoded. MOV audio is commonly AAC or uncompressed PCM, and the reader decodes PCM itself without the browser. The file is read in pieces, so a MOV of several gigabytes does not have to fit in memory. Apple Lossless (ALAC) audio is the exception: it cannot be read here.
Drop video files hereProcess many files at onceNo upload · processed on this device
Making a game?
Nerulio is a 2D game asset studio first: draw pixel art, cut sprite sheets into animations, pack texture atlases, check autotile tilesets and export them for Godot, Unity, Phaser and other engines. It runs in your browser; files stay on your device.
A MOV (QuickTime) file can hold many audio codecs. Nerulio's reader knows AAC, MP3, Opus, FLAC and the PCM variants (16, 24 and 32-bit integer, float, big- and little-endian, µ-law and A-law). It decodes PCM itself; compressed codecs such as AAC go to the browser's WebCodecs decoder.
Apple Lossless (ALAC) is in neither the reader's codec list nor the WebCodecs registry, so a MOV whose only audio is ALAC cannot be converted here.
Because the video is thrown away, the size of the MOV hardly matters. A ProRes clip is large because of its picture: Apple says ProRes files are up to 30 times larger than HEVC. Its PCM audio at 48 kHz, 24-bit stereo is only 2,304 kbit/s, and the reader fetches the parts of the file it needs rather than loading all of it.
PCM
Uncompressed samples; in a MOV often 16- or 24-bit, big- or little-endian.
ALAC
Apple Lossless; not supported by this reader.
Ranged reading
Fetching only the byte ranges that are needed from a large file instead of loading it whole.
Example: one minute of a ProRes MOV with PCM audio
Reading the audio track first:
$ ffprobe -v error -select_streams a:0 -show_entries stream=codec_name,sample_rate,channels -of default=nw=1 take3.mov
codec_name=pcm_s24le
sample_rate=48000
channels=2
PCM in the MOV 48,000 × 24 bit × 2 = 2,304 kbit/s → 17.3 MB per minute
MP3 192 kbit/s 1.44 MB per minute · WAV here (16-bit) 1,536 kbit/s → 11.5 MB per minute
Nerulio's WAV is 16-bit, so a 24-bit recording loses its last 8 bits of resolution. For editing at 24-bit, extract the audio with a desktop tool instead.
From the MOV to the MP3
In the MOV
In Nerulio
In the MP3
AAC audio
Decoded by the browser (WebCodecs)
LAME 3.100, constant bitrate
PCM audio (16/24/32-bit, big- or little-endian)
Decoded by the reader itself
LAME 3.100, constant bitrate
ALAC audio
Not supported
—
H.264, HEVC or ProRes video
Discarded, never decoded
—
Timecode and other tracks
Ignored
—
Check the result
Open the MOV: even a ProRes file opens and shows its duration, although the preview may stay black.
Run the MP3 and check that the result is as long as the section.
Compare the MP3 size with bitrate × seconds ÷ 8 to confirm the chosen bitrate was used.
Troubleshooting
Symptom
Likely cause
How to check
Fix
The export stops with an error about the audio track on a MOV that plays sound elsewhere
The audio is in a codec the reader does not know, such as ALAC
ffprobe shows codec_name=alac
Convert with FFmpeg, or export again from the editor with AAC or PCM
The MP3 has the wrong audio track
Nerulio takes the primary audio track only
ffprobe lists every audio stream
Extract the other track with FFmpeg (-map 0:a:1)
Progress is slow on a multi-gigabyte MOV
The audio packets are spread across the whole file and must be fetched
Progress still advances
Let it finish, or choose a shorter section; the video is still not decoded
ALAC audio, a specific audio track (-map 0:a:1), or batches.
The audio export of your editing app
When the MOV belongs to a project: export the audio at the project's bit depth.
What this page does not cover
ALAC (Apple Lossless) audio is not supported.
WAV output is 16-bit; a 24-bit source loses depth.
Only the primary audio track is used.
Versions and sources
Nerulio's media suite (tests/media-browser.mjs) checks MP3 and WAV extraction on an H.264/AAC MP4; MOV input and PCM decoding are not part of it. The codec list and the PCM decoding described here come from the reader in Mediabunny 1.58.1, the WebCodecs codec registry and Apple's ProRes page.
Extract audio incrementally with selectable 96–320 kbit/s MP3 or PCM WAV.
Implementation and verified quality
advanced · ranged demux / WebCodecs / LAME WASM. Quality qualification is in progress. Pro/Flagship quality has not been established.
Before you export
Fast cut shrinks to inner keyframes. Precise mode re-encodes; codec availability varies. Temporary outputs use local browser storage when available. Compatibility recording retains its short-clip limits.
Frequently asked questions
What determines the supported size?
Actual device memory, storage and codec support. Tested examples are evidence, not a guarantee for every file.
Are my files uploaded?
This tool processes the files you open on your device without uploading them. Images you explicitly attach to community posts are uploaded separately. Optional engines and models are downloaded from third parties; those requests expose connection information such as your IP address.
Will my work be saved automatically?
No. Images and editing state stay in this tab; media output can use local temporary storage. Changing language preserves your work; reloading, closing the tab, or following a link to another page can clear it.