Offline access

190 TOOLS

Transmute keeps a copy of its own code — the HTML, scripts, styles and fonts that draw a page — so a page opens without waiting on the network. The engines are deliberately not part of that copy. None of them is ever fetched in the background, and none is stored unless you ask for it here, by name, with its size in front of you.

NEED NO ENGINE142 tools0 bytes — the page is enough

EVERYTHING EXCEPT FFMPEG16 tools10.8 MB · 11,366,561 bytes

FFMPEG ALONE32 tools30.8 MB · 32,344,478 bytes

8 of the 9 engines below add up to 10.8 MB between them and cover 16 tools. FFmpeg is the last one, and on its own it is 30.8 MB for 32: 26% of the bytes covers 33% of the tools that need an engine, which is worth knowing before you choose.

Engines

9 FILES THIS ORIGIN SERVES

Each row is a file this site serves as its own file, and the figure beside it is that file’s byte count — the number your browser’s network panel will show. Storing one fetches it once, now, instead of the first time a tool needs it.

FFmpeg WASM30.8 MB · 32,344,478 BYTES · 32 TOOLS
Video container swaps, muting, rotating, trimming, splitting and joining; audio formats, loudness and silence filters; and the one H.264 re-encode offered when a stream copy would not play.
/ffmpeg-core.js /ffmpeg-core.wasm
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libheif1.4 MB · 1,513,632 BYTES · 6 TOOLS
Decoding iPhone HEIC photos, which Canvas cannot open on its own.
/vendor/libheif.js /vendor/libheif.wasm
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qpdf2.3 MB · 2,403,819 BYTES · 4 TOOLS
PDF passwords and permissions — protect, unlock, restrict, and repair a damaged file.
/qpdf.js /qpdf.wasm
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lamejs253 KB · 259,508 BYTES · 17 TOOLS
MP3 encoding — the one codec browsers will decode but not write.
/vendor/lamejs.js
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zxing-wasm1.0 MB · 1,093,289 BYTES · 1 TOOL
Reading QR codes and barcodes out of a dropped image.
/zxing_reader.wasm
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libarchive599 KB · 613,235 BYTES · 1 TOOL
Opening TAR, 7z, RAR, CAB, ISO and CPIO — listing what is inside and extracting it.
/libarchive.wasm
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oxipng160 KB · 164,172 BYTES · 1 TOOL
Real PNG re-compression — the one image job a canvas re-encode cannot do at all.
/squoosh_oxipng_bg.wasm
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Tesseract OCR4.9 MB · 5,088,998 BYTES · 2 TOOLS
Reading printed text out of a photo, screenshot or scan.
/tesseract/tesseract.esm.min.js /tesseract/worker.min.js /tesseract/tesseract-core-simd-lstm.js /tesseract/tesseract-core-simd-lstm.wasm /tesseract/eng.traineddata.gz
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Print typefaces225 KB · 229,908 BYTES · 1 TOOL
The five variable faces Markdown to PDF embeds in the document it prints — Newsreader, Outfit, Syne and JetBrains Mono.
/fonts/print/newsreader-latin-wght-normal.woff2 /fonts/print/newsreader-latin-wght-italic.woff2 /fonts/print/outfit-latin-wght-normal.woff2 /fonts/print/syne-latin-wght-normal.woff2 /fonts/print/jetbrains-mono-latin-wght-normal.woff2
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For 12 audio tools, FFmpeg is decided per file. Those tools hand your file to the browser’s own audio decoder first, and only reach for the 30.8 MBcore if that decoder refuses it. Which files get refused differs between Safari, Chrome and Firefox, and between versions of each. So they are neither “works offline” nor “doesn’t” — an m4a that one browser opens on its own is an m4a another sends to FFmpeg. Storing the core is what makes the answer the same every time.

Storage

ON THIS DEVICE, IN THIS BROWSER

Reading what is stored…

That removes both caches this site owns: every engine you stored, and the copy of the site’s own pages. It does not touch transmute-recent-outputs, the single localStorage key that remembers the names of your last eight downloads — that is a different thing in a different store, and clearing site data in your browser is what removes it. It also leaves the service worker registered, so your next visit will keep the two pages it precaches: the home page and the offline notice. No engine comes back without you asking again.

What offline does not cover

THE HONEST EDGES

A tool's own code arrives as a chunk of JavaScript that is cached the first time you open that tool's page. Store every engine here and a page you have never visited will still want the network once.
Browsers evict storage as a whole, not in pieces, and they do it without telling the page. What is stored today may be gone tomorrow — which is why this page re-reads rather than remembering, and why a tool never claims an engine it has not checked for.
This is per browser, per device, per profile. Storing FFmpeg here does nothing for your phone, and nothing for a private window.
142 of the 190 tools reach no engine at all — they run on Canvas, Web Audio, WebCodecs and ordinary JavaScript. There is nothing to store for them and nothing missing when you are offline.
A page served from the cache is the page as it was when you last loaded it. Pages are always fetched from the network first and only fall back to a stored copy when the network genuinely fails, so a stale one can only appear when you are actually offline.