Does Subformer upload my file to a server?

No. The file converter runs entirely in your browser using the WebCodecs API. Your file never leaves your device - no upload, no server processing, no tracking of the file content.

Which formats can I convert?

Video: MP4, MOV, MKV, WebM (both as input and output). Audio: MP3, WAV, OGG, AAC, M4A. Most common audio codecs are also read as input: AAC, MP3, Opus, Vorbis, FLAC, and several PCM variants.

Can I convert MP4 to MP3?

Yes. Pick an MP4 (or any video file) and choose MP3 as the output. The converter extracts and re-encodes the audio track locally in your browser.

Can I convert MOV to MP4?

Yes. MOV and MP4 share the same underlying container (ISO-BMFF) so most MOV → MP4 conversions are fast remuxes without re-encoding video.

Is there a file size limit?

There is no server-side limit because nothing is uploaded. In practice, most browsers handle files up to a few hundred megabytes comfortably. Files over 500 MB will show a memory warning - very large files may exhaust your browser's memory.

Why does the first MP3 conversion take a moment on Firefox?

Firefox doesn't ship a built-in MP3 encoder via WebCodecs, so the converter downloads a small LAME WebAssembly encoder (~100 KB) on first use. It's cached after that. Chrome and Safari encode MP3 natively with no extra download.

Which browsers are supported?

Any modern browser with WebCodecs: Chrome 94+, Edge 94+, Firefox 130+, Safari 16.4+. If your browser is older, the landing page still loads but the converter will show an 'Unsupported browser' error on your first conversion.

Can I convert multiple files at once?

Batch conversion is on the roadmap. For now, convert one file at a time. You can run multiple browser tabs in parallel if you need to.

Subformer

Accede

Gratis · Sine inscriptione · In navigatore tuo currit

Conversor Fasciculorum Online Gratuitus pro Video et Audio

Converte MP4, MOV, MKV, WebM, MP3, WAV, OGG, et alia directe in navigatore tuo. Acceleratio hardware per WebCodecs - celer, privatus, et nihil ad servitorem mittitur.

Quomodo fasciculum online convertere

01
Deponere video vel audio fasciculum
Trahe fasciculum super convertitorem, aut clicca ut unum seligas - operatur cum MP4, MOV, MKV, WebM, MP3, WAV, et plurimis formatibus communibus.
02
Elige formatum exitus
Elige praesettum ad unam pressionem (e.g. MP4 → MP3) vel selige quemvis formatum e menu pendulo.
03
Converte et recupera
Preme "Convert". Navigatro reliqua curat - observa barram progressus, deinde desume novum tuum fasciculum.

Omnia quae necesse sunt ad media convertenda

Privatum ex consilio

Fasciculus tuus numquam exit e dispositivo tuo. Legere, decodificare, codificare et scribere omnia in navigatro tuo fiunt - nos ne nomen fasciculi quidem videre possumus.

Acceleratum per hardware

Alimentatur a WebCodecs, eodem motore video quo navigatro tuo utitur pro YouTube et Netflix. Conversiones MOV ↔ MP4 saepe sunt celeres remuxes sine re-encoding.

Extractio video ↔ audio

Submite video, elige formatum audio, et accipe tantum audio. Idoneum ad transformandas colloquia, lectiones et podcast in MP3.

MP4 fast-start

Output MP4 producitur cum suo moov atom in initio fasciculi - idoneus ad streaming et rectam exsecutionem in interrete.

Sine installatione

Nulla applicatio desktop, nullus plugin, nulla versio ffmpeg in linea mandatorum. Aperi paginam, depone fasciculum, accipe eventum.

Annullare quovis tempore

Conversiones in fundo tabulae currunt et medio itinere annullari possunt si mentem mutas.

Formata supportata

Converter legit plerosque communes fasciculos audio et video et exportat in quolibet formatum infra.

Formata video

MP4 - Contenerium maxime compatibile. Ubique operatur. Cum fast-start ad celerem lectionem in interrete.
MOV - Contenitor QuickTime. Eadem structura ac MP4 - remuxatio celeris.
MKV - Matroska. Continens flexibilis, a multis fontibus usitatus.
WebM - Formatum nativum web, optimum pro video online cum VP8 / VP9 / AV1.

Formata audio

MP3 - Universale supportatum. Bona electio pro podcastibus et communione musicae.
M4A / AAC - Audio AAC in continitore MP4 (M4A) vel fluxu AAC rudis (ADTS). Communis in machinis Apple.
WAV - Audio PCM non compressum. Optimum pro processibus editionis.
OGG - Contenerium fonte aperto, plerumque cum audio Opus vel Vorbis.

Conversiones populares

Paginæ dedicatæ ad unam pressionem cum instructionibus specificis pro formatis ad opera frequentissima.

Conversor Fasciculorum Online Gratuitus pro Video et Audio

Quomodo fasciculum online convertere

Deponere video vel audio fasciculum

Elige formatum exitus

Converte et recupera

Omnia quae necesse sunt ad media convertenda

Privatum ex consilio

Acceleratum per hardware

Extractio video ↔ audio

MP4 fast-start

Sine installatione

Annullare quovis tempore

Formata supportata

Formata video

Formata audio

Conversiones populares

Quaestiones saepe rogatae

Editor Subtitulorum

Interpres Video AI

Editor video per interrete

Quomodo fasciculum online convertere

Deponere video vel audio fasciculum

Elige formatum exitus

Converte et recupera

Omnia quae necesse sunt ad media convertenda

Privatum ex consilio

Acceleratum per hardware

Extractio video ↔ audio

MP4 fast-start

Sine installatione

Annullare quovis tempore

Formata supportata

Formata video

Formata audio

Conversiones populares

Quaestiones saepe rogatae

Num Subformer fasciculum meum in servitorem mittit?

Quae formata convertere possum?

Possumne MP4 in MP3 convertere?

Possumne MOV in MP4 convertere?

Estne limitatio magnitudinis fasciculi?

Cur prima conversio in MP3 in Firefox paulisper tardatur?

Quos navigatores sustentantur?

Possumne plures fasciculos simul convertere?

Instrumenta correlata a Subformer

Editor Subtitulorum

Interpres Video AI

Editor video per interrete