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Privacy

Conversion, without the cloud.

WebAssembly compiles FFmpeg, libheif, and pdf.js into your browser tab. Your file gets converted by code running on your CPU — never on someone else's server. Verify it yourself with DevTools.

BY MORPH4 MIN READUPDATED APRIL 2026

Every time you use a traditional online converter, your file gets uploaded to someone else's server. Your photos, documents, and videos sit on infrastructure you don't control, processed by code you can't inspect. Most services say they delete your files after an hour. Some don't delete them at all.

There's a better way. Modern browsers can convert files entirely on your device using a technology called WebAssembly. No upload. No server. No trust required.

How traditional online converters work

When you use a typical file converter, here's what happens behind the scenes:

1. Your browser uploads the file to the converter's server
2. The server processes the file (often using FFmpeg, ImageMagick, or LibreOffice)
3. The converted file is stored temporarily on their server
4. You download the result
5. The server (hopefully) deletes both files eventually
During this process, a copy of your file exists on a server you don't own. For personal photos, medical documents, financial spreadsheets, or confidential contracts, this is a real privacy risk.

How client-side conversion works

Client-side conversion skips the server entirely. Tools like Morph compile powerful conversion libraries (like FFmpeg for video or libheif for HEIC images) into WebAssembly — a binary format that runs at near-native speed inside your browser.

Here's what happens instead:

1. You drop a file onto the page
2. JavaScript reads the file from your local filesystem
3. WebAssembly processes the conversion in a sandboxed environment
4. The converted file is created in browser memory
5. You download the result directly from your own browser
Your file never leaves your device. There is no upload, no server processing, no temporary storage. Even if you disconnect from the internet after loading the page, the conversion still works.

What formats can you convert without uploading?

Morph supports over 250 file formats, all processed client-side:

How to verify no upload happens

Don't take our word for it. You can verify this yourself:

Open DevTools. In Chrome, press F12 and click the Network tab.
Drop a file on Morph. Watch the network tab. You'll see zero outbound requests containing your file data.
Go offline. Turn off WiFi, then try a conversion. It still works.

This is the litmus test. If a converter stops working when you disconnect from the internet, it's uploading your files. If it keeps working, it's genuinely client-side.

Try it now

Morph converts 250+ formats with zero uploads, zero accounts, and zero cost. Drop any file and see for yourself.

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