Does Subformer upload my file to a server?

No. Every conversion runs entirely in your browser. 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. Audio: MP3, WAV, OGG, AAC, M4A. Images: JPG, PNG, WebP, HEIC, BMP, GIF. Documents: PDF (input and output). Most common audio codecs (AAC, MP3, Opus, Vorbis, FLAC, PCM) are accepted as media input.

Can I combine JPGs into a PDF?

Yes. Drop one or more JPG or PNG files and pick PDF as the output - each image becomes a page in a single PDF. We embed the original image bytes without re-encoding, so there's no quality loss.

Can I convert HEIC photos from my iPhone?

Yes. Pick HEIC to JPG, HEIC to PNG, or HEIC to PDF. The converter uses a WebAssembly libheif build to decode HEIC locally - your photos never leave your device.

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.

Can I convert MOV to MP4?

Yes - and it's fast. MOV and MP4 share the same underlying container, so most MOV to MP4 conversions are remuxes without re-encoding video.

Is there a file size limit?

No server-side limit - nothing is uploaded. Files over 500 MB trigger a warning because browsers can run out of memory on very large files.

Which browsers are supported?

Any modern browser: Chrome 94+, Edge 94+, Firefox 130+, Safari 16.4+. Image and PDF conversions also need WebAssembly support, which every modern browser has.

Can I convert multiple files at once?

For image-to-PDF, yes - drop several images and we combine them into a single PDF. For other conversions, batch is on the roadmap. You can open multiple browser tabs in parallel as a workaround.

What's the difference between the WebCodecs and FFmpeg engines?

Both engines (used for video and audio) run entirely in your browser - no file is ever uploaded. WebCodecs is the default: it uses your browser's hardware-accelerated media APIs so conversions are fast and ship no extra wasm. FFmpeg (wasm) is a pure-software fallback built from the same ffmpeg project desktop tools use - it supports more codecs but is slower and downloads ~22 MB on first use.

When should I pick the FFmpeg engine?

Switch to FFmpeg if the WebCodecs engine fails with an 'unsupported codec' error, if your browser lacks a decoder (e.g. older Safari with VP9), or if you need strict H.264 + AAC output for maximum device compatibility. For everyday MP4 / MOV / MKV / WebM / MP3 / WAV conversions, WebCodecs is faster and recommended.

Is FFmpeg-wasm safe to run in the browser?

Yes. @ffmpeg/ffmpeg is an open-source WebAssembly build of the official FFmpeg project. It runs inside the browser sandbox with no network access - all processing happens on your device. We fetch the wasm core once from a public CDN and execute it locally.

Subformer

Accede

Gratis · Sine inscriptione · In navigatore tuo currit

Conversor Online Gratuitus Fasciculorum

Converte video, audio, imagines, et PDFs omnino in navigatro tuo - MP4, MOV, MP3, WAV, JPG, PNG, HEIC, PDF, et alia. Velox, privatus, nihil transferitur.

Unum vel plura demitte - video, audio, imaginem, PDF, subtitulos, data, documenta. Pro singulis documentis proposita, fasciculum converte, ZIP depone.

Elige categoriām ut incipias

Quaeque conversio paginam dedicatam habet cum consiliis pro singulis formatibus. Elige proximum exemplar pro id quod tibi opus est.

Quomodo fasciculum online convertere

01
Depone fasciculum tuum
Trahe video, audio, imaginem, aut PDF in conversorem - aut preme ut unum ex instrumento tuo seligas.
02
Elige formatum exitus
Elige praeconfigurationem ad unum clic aut aperi paginam conversionis dedicatam (JPG in PDF, HEIC in JPG, MP4 in MP3, et alia).
03
Converte et recupera
Preme "Convert". Navigatro reliqua curat - observa barram progressus, deinde desume novum tuum fasciculum.

Omnia necessaria ad conversionem fasciculorum

Privatum ex consilio

Fasciculus tuus numquam e dispositivo tuo exit. Decodificatio, codificatio et scriptio omnia in navigatro tuo fiunt - nec etiam nomen fasciculi videre possumus.

Acceleratum per hardware

Video et audio per WebCodecs transeunt - idem machina quam navigātor tuus ad YouTube et Netflix utitur. Fluxus imaginum et PDF utuntur canvas + pdf-lib, et plene compatibiles cum GPU sunt.

Sustentatio Imaginum & PDF

Coniunge JPG in PDF, converte imagines HEIC ex tuo iPhone, converte paginas PDF in imagines, vel transi inter JPG, PNG, et WebP.

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 legīt plūrimōs rēgularēs generēs fasciculōrum et exportat in quīlibet formatum infra.

Video

MP4 - Fasciculus maxime compatibilis. Ubique operatur. Productus cum fast-start ad celerem reproductionem 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.

Audio

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

Imago

JPG - Prāevalēns forma cum prōditiōne in interrētē. Fasciculī parvī, fere ūniversālis supportātiō, nulla transparentia.
PNG - Sine perdita cum transparentia canalis alpha. Optimum pro capturis schermi, logotypis, et graphicis.
WebP - Formatum modernum a Google. Superior est JPG et PNG in magnitudine fasciculi ad eandem qualitatem.
HEIC - Formatum photographicum praedefinitum iPhone Apple. Circiter dimidium magnitudinis JPG — illud localiter decodimus per WebAssembly libheif.

Documentum

PDF - Universale formatum documentorum. Inserre imagines JPG / PNG / HEIC in unum PDF, vel renderare paginas PDF rursus in imagines. PDF multipaginae exeunt ut ZIP paginarum.

Textus et Subtituli

TXT / Markdown - Textus simplex et Markdown. Verte in PDF pro distributione imprimibili. Tituli Markdown, listae et bullets redduntur cum stylo basico.
SRT / VTT - Fasciculi subtituli et captionum. Converte inter SRT et WebVTT, vel remove signacula temporis ut transcriptus in textu plano obtineatur.

Data et Folia Computatoria

CSV / JSON / YAML - Formati datorum tabularium et structurarum. Converte inter quacunque duo pro scriptis, API, et fasciculis configurationis.
XLSX (Excel) - Fasciculi Excel. Data extrahuntur ad CSV vel JSON pro scriptis et canalibus datorum.

Omnes conversiones

Paginae unicuique clic dedicatae cum instructionibus specificis formati pro qualibet conversione quam sustinemus.

Elige categoriām ut incipias

Video

Audio

Imago

PDF & Documenta

Textus et Subtituli

Data et Folia Computatoria

Quomodo fasciculum online convertere

Depone fasciculum tuum

Elige formatum exitus

Converte et recupera

Omnia necessaria ad conversionem fasciculorum

Privatum ex consilio

Acceleratum per hardware

Sustentatio Imaginum & PDF

Extractio video ↔ audio

MP4 fast-start

Sine installatione

Annullare quovis tempore

Formata supportata

Video

Audio

Imago

Documentum

Textus et Subtituli

Data et Folia Computatoria

Omnes conversiones

Video et Audio

Imago & PDF

Textus et Subtituli

Data et Folia Computatoria

Documenta

Comprimere

Quaestiones saepe rogatae

Num Subformer fasciculum meum in servitorem mittit?

Quae formata convertere possum?

Possumne JPG in PDF coniungere?

Possumne imagines HEIC ex meo iPhone convertere?

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?

Quid interest inter machinas WebCodecs et FFmpeg?

Quando debeo eligere machinam FFmpeg?

Instrumenta correlata a Subformer

Coniunge ad PDF

Rotate PDF

Rota Imaginem

Editor Subtitulorum

Interpres Video AI

Editor video per interrete