How to Tell If a File Converter Is Actually Safe to Use

The Main Risks

• File storage: Your document is kept on their server longer than needed, potentially accessed by staff or breached.
• Data harvesting: Some free tools monetise by selling usage data or metadata from your files.
• Malware in downloads: The downloaded "converted" file contains malicious scripts.

How to Vet a Tool

• Check for HTTPS. Non-HTTPS tools have no business touching your files.
• Read the privacy policy. Look specifically for how long files are stored and whether they share data with third parties.
• Test with a dummy file first. Don't upload sensitive documents to an untested tool.
• Check the download. Scan the output file with VirusTotal before opening it.
• Look for client-side processing. Tools that process locally (in your browser) never upload your file at all.

Signs of a Trustworthy Tool

• Clear, specific privacy policy.
• States explicitly that files are deleted after X minutes.
• Client-side processing (your file never leaves your device).
• No sign-up required to use the tool.