How in-browser processing works

The usual way — and our way

Most online converters work like this: you upload your file to their server, the server converts it, and you download the result. Your contract, ID scan, or family photo makes a round trip through someone else’s computer, subject to their retention policy and security.

Convertly Tools works differently. Modern browsers contain remarkably capable image and document machinery, and our tools run entirely on it. The page you load contains all the code needed to do the conversion; your file is opened, processed, and re-encoded in your browser’s memory, on your device. There is no upload step — not a fast one, not an encrypted one, none.

What each tool uses

Every current tool runs on one of these in-browser technologies:

• PNG, JPG & WebP converters: Your browser’s built-in image engine (Canvas API)
• HEIC to JPG: A HEIC decoder compiled to WebAssembly, shipped inside this site’s own code
• Image Compressor & Resizer: Canvas API re-encoding on your device
• JPG/PNG to PDF, Merge, Split: An in-browser PDF library (pdf-lib) running in the page
• PDF to JPG & PDF Compressor: The same PDF renderer your browser uses (pdf.js), loaded from this site
• “Download all” ZIPs: Assembled in your browser’s memory (client-zip)

None of these make network requests with your file’s contents. The HEIC decoder deserves a special note: decoding Apple’s format needs real codec work, which we ship as WebAssembly inside the site’s own JavaScript — downloaded once as ordinary site code, then run locally.

Verify it yourself in two minutes

You don’t need to trust this page — your browser can prove it:

• Open any tool, for example PNG to JPG.
• Open your browser’s developer tools (F12 or right-click → Inspect) and switch to the Network tab.
• Drop in a file and convert it.
• Watch the request list: you’ll see the page load its own scripts — and no request carrying your file anywhere. The conversion happens even if you disconnect from the internet after the page loads.

What does leave your device

Honesty requires the full picture. Like most websites, we load the site’s own code and fonts from our server, and — only if you accept the cookie banner — Google Analytics records page-level usage (which tools are popular, never file contents). If ads are shown, Google AdSense loads its script. None of these ever receive your files or anything derived from them. Details in our Privacy Policy.

What this means in practice

• Confidential documents stay confidential — contracts, statements, and IDs are processed without ever being transmitted.
• There’s no server queue, so conversion starts instantly.
• There’s nothing for us to store, leak, or delete — we never had your file.
• Large files are limited only by your device’s memory, not by an upload cap.

If we ever add a tool that requires server-side processing, its page will say so explicitly before you use it — that commitment is in our Privacy Policy.