Are Online File Converters Safe? What You Need to Know

Think about the last time you used an online file converter. You uploaded a document, an image, or a video to some website, waited for it to process, and downloaded the result. Easy. Fast. Free.

But have you ever stopped to think about what happened to that file after you uploaded it?

What Most Online Converters Do With Your Files

When you upload a file to an online converter, your file travels from your computer to a server, usually in a data center you know nothing about, operated by a company you have never heard of. Once on their server, your file is:

1. Received and stored (temporarily or permanently)
2. Processed by their conversion engine
3. The output is stored and a download link is generated
4. The original and output may or may not be deleted after a certain period

The problem is step 4. Many converters keep uploaded files for hours, days, or even indefinitely. Their privacy policies (if they even have one) are often vague about retention periods.

Real Risks

• Data breaches: If the converter's server gets hacked, your files are exposed
• Employee access: Server operators can potentially access uploaded files
• No encryption: Some services transfer files over unencrypted HTTP
• Metadata harvesting: Your documents contain author names, GPS coordinates (in photos), revision history, and more
• Compliance violations: Uploading client documents to random servers may violate GDPR, HIPAA, or your company's security policies

The Offline Alternative

Desktop converters like Filoshi process everything on your machine. The file never touches a server. There is nothing to breach because there is no upload. This is privacy by design rather than privacy by policy.

Even Filoshi's free web converter runs entirely in your browser using WebAssembly. The video or audio file you drop onto the page is processed by FFmpeg running inside your browser tab. No bytes leave your computer.

When Online Converters Are Fine

For truly non-sensitive files like a random meme you want to resize or a public domain clip you need to re-format, online converters are convenient and the risk is negligible. The key is being honest with yourself about what counts as "non-sensitive."

Tax returns, medical records, legal contracts, personal photos, corporate documents? Use an offline tool. Always.