BoltDeck

Privacy-first tools: your files never leave your device

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Most people don’t think about where their PDF, photo or spreadsheet goes when they use a free online tool. With BoltDeck, the answer is simple: nowhere. Your files never leave your device. All processing happens directly in your browser.

This page explains what that means, how it works, and — most importantly — how you can check it yourself instead of just taking our word for it.

What usually happens when you “upload” a file

On most online tool sites, using a tool means sending your file to the company’s servers:

  1. Your file travels over the internet to a computer you don’t control.
  2. It’s processed there — merged, compressed, converted.
  3. The result is sent back to you, and a copy may stay on their servers for minutes, hours or longer.

That might be fine for a holiday photo. It’s less fine for a contract, a payslip, a customer list or an invoice with someone’s address on it. You’re trusting a company you’ve probably never heard of to handle your data properly and delete it when they say they will.

What happens on BoltDeck

BoltDeck works the other way round. Instead of sending your file to the tool, we send the tool to you:

  1. When you open a tool, your browser downloads the tool itself — a small program written in JavaScript.
  2. When you pick a file or type something, your browser reads it locally, on your phone or computer.
  3. The work — creating a QR code, building an invoice PDF — is done by your own device.
  4. The result is created in your browser’s memory and saved straight to your device as a download.

At no point is your file or the text you type sent to us or to anyone else. There’s no upload step, because there’s nothing on our side to upload to: BoltDeck has no servers that process files, no database and no user accounts. The whole site is a set of static files.

Heavier building blocks, such as the engine that writes PDF files, are only downloaded the first time you actually need them, so pages stay fast even on a cheap phone. Some of them use WebAssembly — a way of running fast, compiled code in the browser. For example, when you convert an iPhone HEIC photo in a browser that can’t open HEIC by itself, the image converter downloads a HEIC decoder built with WebAssembly. It works on the same principle: the code comes to you, your data stays with you. (The open-source parts we use are listed on our licences page.)

Check it yourself

You don’t have to trust us. Here are two ways to see for yourself that nothing is uploaded.

The airplane mode test (anyone can do this)

  1. Open a tool, for example the invoice generator or the QR code generator.
  2. Try it once so everything it needs has loaded — make a test QR code, or download a test invoice.
  3. Switch on airplane mode, or turn off Wi-Fi and mobile data.
  4. Without reloading the page, use the tool again with your real details. It still works, and you can still download the result.

A tool that needs to upload your file to a server simply can’t work without an internet connection.

The developer tools test (for the curious)

  1. On a computer, open a tool and press F12 (or Cmd + Option + I on a Mac) to open the browser’s developer tools.
  2. Go to the Network tab.
  3. Use the tool: pick a file, type, click download.
  4. Watch the list. You’ll see the tool’s own files loading from boltdeck.eu, but no request carrying your file or your text.

What we do and don’t collect

We’d rather be precise than reassuring, so here’s the full picture:

  • Your files and what you type: never collected. They stay on your device.
  • Things you ask us to remember: some tools can remember settings, like your business details in the invoice generator — but only if you tick the box, and only in your own browser. You can delete them at any time on our privacy page.
  • Visitor statistics: we use Cloudflare Web Analytics to count page views. When a page loads, a small anonymous message tells us which page was opened, which site you came from, your browser type and roughly which country you’re in. It doesn’t use cookies, doesn’t identify you, and never includes your files or anything you type into a tool.
  • Delivering the site: like every website, the pages are sent to you by a server (Cloudflare), which has to see your IP address to do that and to protect the site against attacks.
  • Cookies: none. If we add advertising in the future, we’ll ask for your permission first, and every tool will keep working if you say no.

The details are in our privacy policy.

What we can’t protect you from

Being honest about the limits matters too:

  • Browser extensions you’ve installed can usually read the pages you visit, including BoltDeck. Only install extensions you trust.
  • Shared computers: files you download end up in that computer’s Downloads folder. Don’t tick “remember my details” on a computer other people use.
  • Malware on your own device is outside anything a website can protect against.

Why do it this way?

Because for most everyday tasks, there’s no good reason for your files to travel to a server at all. Modern phones and computers are more than powerful enough to make a QR code, build an invoice or resize a photo. Doing the work on your device is more private, often faster (there’s no upload or download wait), and it means we don’t have to store or protect anyone’s data — because we never have it.

That’s what we mean by small tools, instant results.