twineconvert

301converters · in-browser · private by design

Convert Any File.
Privately.

Pick a conversion from the chips on the right, or drop a file below and we'll route you to the right tool. 301 converters across 9 categories, straight from your browser.

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Popular:HEIC → JPGPDF → DOCXMP4 → MP3Compress PDFOFX → CSV

Formats supported

Hundreds of formats, thousands of conversion types.

The everyday ones, the niche ones, and a few you've probably never heard of , 301 tools across 9 categories. Every conversion gets its own page with a guide and FAQ.

Browse all formats →

Data security

Your files, handled privately.

Every conversion runs in your browser via WebAssembly. Files never travel to a server because there is no server. No daily quota, no upload size cap, no signup, no account.

How it works →

Browse the engine

Pick a converter.

Every tile is a dedicated page with the conversion UI, format guide, and FAQ.

See all 301 alphabetically

Personal data exports

18 tools

Apple Health, WhatsApp, Discord, Twitter / X, Instagram, Facebook. Extract your data into open formats.

Genealogy, citations, ham radio, chess

28 tools

Niche professional formats most generic converters don't bother with. GEDCOM, BibTeX, ADIF, PGN.

Design, color, 3D, music, embroidery

38 tools

Adobe ASE palettes. Color-grading LUTs. STL/OBJ/3MF mesh interchange. MIDI, MusicXML. DST/PES/JEF/EXP for Singer, Brother, Janome, Bernina embroidery machines.

FAQ

Common questions

Is twineconvert really free?
Yes, completely free for every conversion, with no daily quotas, no signup, no upgrade-to-remove-watermark gates. The site runs on display ads in the SEO content areas of each tool page; the conversions themselves never have ads or limits. No paid tier exists.
How is it possible that nothing is uploaded?
Modern browsers ship a near-complete operating system: WebAssembly runs C / C++ / Rust libraries at near-native speed, the File API reads files directly off your disk, and the Blob API lets us hand the converted file back as a download, all without ever sending bytes to a server. The same libraries (FFmpeg, libheif, pdfjs, mammoth, web-ifc, jsquash, etc.) that upload-based converters run on their servers, we ship as WASM into your browser tab.
Is there a file size limit?
Practically, your limit is whatever your machine can hold in browser memory, usually 1–4 GB of RAM for the conversion's working set. We don't impose an artificial cap. Upload-based converters typically cap at 1 GB on the free tier because their servers cost money per gigabyte; ours don't, because there are no servers.
What about really sensitive files, bank statements, medical records, court documents?
Those are exactly the files this site exists for. A bank statement (OFX, QFX, QBO, QIF) or a medical export (Apple Health, DICOM) sitting on a third-party server, even briefly, is an unnecessary risk. Here, the conversion executes locally in your browser tab, we have no server that could store, log, or even see the file.
Why are some converters slow?
Conversions that involve OCR (image-to-text), heavy video encoding (FFmpeg transcoding), or large 3D meshes (IFC, STL) are CPU-bound and execute on your machine. The WebAssembly runtime is fast (typically 80–95% of native speed) but still bound by your CPU. Upload-based converters feel faster on small files because they trade your privacy for a beefier server; on large files, the upload time often makes them slower overall.
Will my browser hang on a big file?
The conversion runs in a Web Worker (a background thread), so the page stays responsive while it works. You'll see a progress indicator during long operations. If you do hit a memory ceiling, the tab will reload, your file is never lost because it never left your disk.
Do you support batch conversion?
Not yet, the current UI is one file at a time per tool page. Batch conversion is on the near-term roadmap; the engine itself is stateless and supports it, the UI just isn't wired up yet.

Why in-browser

The case for not uploading your files.

Most online file converters work the same way: you upload your file to their server, their server converts it, you download the result. The trade-off most users don't think about: your file lives on their server, even if briefly.

That matters more for some files than others. A photo of your dog is one thing. A bank statement, a court filing, a private chat export, a medical scan, an unreleased work draft. Those are files where having a copy land on a third-party server is, at minimum, an unnecessary risk.

twineconvert runs the conversion in your browser using WebAssembly compilations of the same libraries the upload-based converters run on their servers (FFmpeg, libheif, pdfjs, mammoth, web-ifc, jsquash, and a few dozen more). The only difference: the conversion executes on your machine instead of theirs.

Practical implications: no upload progress bar, no daily quota, no file size cap, no signup, no email, no "upgrade to convert without watermark." You drop a file, your browser does the work, you download the result.