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SwiftTooly

Guides

How to do everyday file, image and document work without handing your data to a server — and how to verify, rather than trust, where your files actually go.

Articles5

Are online PDF tools safe?

Most free PDF tools upload your document to a server you know nothing about. Here is what that actually means, when it matters, and how to check whether a given tool does it.

· 6 min read

Which web tools keep working offline

If a web tool still works after you disconnect from the internet, it cannot be uploading your files. That makes the offline test the simplest privacy check available.

· 5 min read

Why your QR code stopped working

A QR code printed on a thousand flyers that no longer scans is an expensive problem. The causes are predictable, and most of them are decided before anything is printed.

· 6 min read

Social media image sizes, and why platforms crop

The dimensions are the easy part. What actually ruins posts is knowing where each platform crops, what its own interface covers, and which region survives every view.

· 5 min read

How to check whether a website uploads your files

Claims about privacy are cheap. These two tests take under a minute each and give you a definitive answer about where your file actually goes.

· 5 min read

01

What these guides are for

Almost every article about online file tools is either a product page or a list of alternatives. These are neither. They are about the mechanics: what actually happens to a document when you drop it into a web page, which operations genuinely need a server and which do not, and how to check any given tool rather than trusting what it says about itself.

That framing exists because the usual advice — read the privacy policy — does not work well here. A policy describes intent at a moment in time. It can be revised, and it says nothing verifiable about where processing happens. The more useful question is architectural, and it happens to be one you can answer yourself in under a minute with tools already built into your browser.

02

The two tests worth knowing

The network test: open developer tools, switch to the Network tab, and use the tool. If your file is uploaded you will see a request roughly the size of your file. If nothing of that size appears, nothing was sent.

The offline test: load the page, disconnect from the internet, then use the tool. If it completes, the processing happened on your device — a tool that transmits your file cannot work without a connection. This one needs no technical knowledge and cannot be faked.

Both are covered in detail in the guides below, along with how to read the results fairly — small analytics requests are not file uploads, and a tool that fails the offline test is not necessarily untrustworthy, just server-dependent.

03

Who writes these

Everything here is written by Ahmed Kobbi, who builds and maintains SwiftTooly — the tools, the code, the copy and the design. That means the technical claims come from someone who implemented them rather than from someone summarising other articles, and it also means there is an obvious interest to declare: this site benefits if you conclude that local processing is worth preferring.

The response to that is to make everything checkable. Where a guide claims a tool behaves a certain way, it tells you how to verify it yourself, including on this site’s own tools. Where something genuinely needs a server, it says so plainly rather than pretending otherwise. You can read more about how the site is built on the about page.