Why Browser-Based File Conversion Is Safer
Every day, millions of people upload sensitive files to online conversion services without a second thought. Tax documents, personal photos, business contracts, medical records — all sent to unknown servers operated by companies with vague privacy policies. There's a fundamentally better approach: browser-based conversion, where your files never leave your device.
How Traditional Online Converters Work
When you use a typical online file converter, here's what happens behind the scenes:
- Your file is uploaded to the service's server over the internet.
- The server stores your file (temporarily, they claim).
- Server-side software processes the conversion.
- The converted file is sent back to you for download.
- Your original file is (supposedly) deleted from their server.
At every step, your data is exposed to risk. During upload and download, it could be intercepted. While stored on the server, it could be accessed by employees, hackers, or government agencies. And the "deletion" step? You have absolutely no way to verify it actually happens.
The Real Risks of Server-Side Conversion
- Data breaches — Conversion services are attractive targets for hackers because they store a constant stream of user files. A breach could expose millions of documents at once.
- Data mining — Some services analyze uploaded files to extract data for advertising, AI training, or resale. Their terms of service often grant them broad usage rights.
- Employee access — Server administrators can potentially view any file stored on their systems. For sensitive documents, this is a serious concern.
- Legal compliance — Files stored on servers in certain jurisdictions may be subject to government access requests. Your converted tax return could be stored on a server in a country with very different privacy laws.
- Incomplete deletion — Even when services delete files, data may persist in backups, caches, CDN nodes, or log files for weeks or months.
- Network interception — Uploading files over the internet, even with HTTPS, adds attack surface that doesn't exist with local processing.
How Browser-Based Conversion Works
Browser-based converters like This 2 That take a completely different approach:
- You open the webpage. The conversion code (JavaScript/WebAssembly) downloads to your browser.
- You select a file. It's read directly by your browser — it never leaves your device.
- The conversion runs locally on your computer or phone using your device's processing power.
- The converted file is saved directly to your device.
There is no upload step. There is no server-side storage. There is no download step. Your files exist only on your device throughout the entire process.
Convert files the safe way — everything stays on your device.
Try This 2 That →How Can You Verify This?
Don't take our word for it. You can verify that a converter is truly browser-based:
- Open your browser's Network tab — Press F12, go to the Network tab, and perform a conversion. If no files are uploaded, you won't see any large outgoing requests during conversion.
- Disconnect from the internet — Load the converter page, then turn off Wi-Fi. If the conversion still works, it's truly local.
- Check the source code — Browser-based tools use client-side JavaScript, which is visible and auditable in your browser's developer tools.
What About Performance?
A common concern is whether browser-based conversion is as fast as server-based. The answer depends on the task:
- Image conversion — Instant. Modern browsers handle image processing extremely efficiently.
- Document conversion — Fast. PDF merging, Excel parsing, and similar tasks run in milliseconds to seconds.
- Audio conversion — Good. WebAssembly-based encoders are highly optimized.
- Video conversion — Slower than server-side, but getting faster. Large video files may take a few minutes depending on your device.
For most conversion tasks, browser-based tools are actually faster than server-based ones because they skip the upload and download time. A 10MB image converts instantly locally, versus waiting 10-30 seconds for upload, processing, and download on a server-based tool.
When Privacy Matters Most
Browser-based conversion is especially important when working with:
- Financial documents — Tax returns, bank statements, invoices.
- Medical records — Health information protected by regulations like HIPAA.
- Legal documents — Contracts, court filings, attorney-client correspondence.
- Personal photos — Private images you wouldn't want on someone else's server.
- Business data — Trade secrets, customer data, internal reports.
- Identity documents — Passports, driver's licenses, social security cards.
The Bottom Line
Every time you upload a file to an online converter, you're trusting a third party with your data. Browser-based conversion eliminates that trust requirement entirely. Your files stay on your device, period.
This 2 That offers 50+ conversion tools that all run locally in your browser. Convert images, documents, audio, video, and data — without uploading anything. Convert anything. Upload nothing.