About Expert Tools Kit

What this site is

Expert Tools Kit is a collection of 154 browser-based utilities — image compression, PDF merging, passport photos, PDF signing, hashing, unit conversion, colour maths, tax calculation and fifty-odd others. All of them are free, none of them require an account, and none of them upload your files.

That last point is the whole reason the site exists. Most free online tools work by taking your file, sending it to a server, processing it there, and sending the result back. It is the obvious architecture, it is cheap to build, and it means your document sits on someone else's hardware for as long as their retention policy says it does.

Why local processing instead

Browsers became capable of this work some years ago and most tool sites never updated. The File API reads local files without a network request. Canvas and WebCodecs handle image encoding. WebAssembly runs PDF libraries and machine learning models at close to native speed. Web Crypto does hashing in the browser's own C++ implementation. Web Workers keep all of it off the main thread so the page stays responsive.

Everything on this site is built on those. The practical consequences are worth being concrete about:

• No file size limit. The ceiling is your device's memory, not a server quota. Upload-based competitors cap their free tiers at 5–100 MB because bandwidth costs them money.
• No queue. There is no shared server to be busy. A 200-page PDF merges as fast as your laptop can do it.
• No retention question. We cannot delete your file on a schedule, because we never receive it.
• Works offline. After one visit, the service worker has cached the shell and every pure-JavaScript tool.

The cost is real too, and worth stating. Heavy tools have a one-time download — the background remover fetches a 42 MB model, OCR fetches a language pack, the PDF tools fetch pdf-lib. Older phones are slower than a server would be. And we cannot offer anything that genuinely requires a backend, which is why there is no plagiarism checker and no site crawler here.

Who builds it

Expert Tools Kit is built and maintained by a small independent team of web developers. Every tool is implemented from scratch or on top of a permissively licensed open-source library — pdf-lib, PDF.js, Tesseract, fflate — with the licence checked before it goes in. There is no venture funding, no growth target, and no plan to add an account system.

If a tool gives you a wrong answer, we want to know. The contact page goes to a real inbox.

How the site is funded

Display advertising, and nothing else. There is no paid tier, no credit system and no data sale — the last one is structurally impossible, since your files never reach us.

We limit ourselves to standard banner and native ad units, capped at four per page, always placed below the tool rather than above or inside it. We do not run popunders, push notifications, interstitials, vignettes or social bars. Those formats earn more and make a site worse to use, and we would rather have the traffic than the RPM.

What we collect

Google Analytics 4: page views, referrer, approximate country and browser. It sets its own first-party cookies and Google may combine the data with its other services. There are no user accounts to attach anything to, and it never sees the files you process. Our advertising partners set their own cookies, which the privacy policy covers in detail along with how to opt out.

Technical notes

The site is a fully static export — plain HTML, CSS and JavaScript on a CDN, with no application server anywhere. Each tool's code is loaded only on its own page, and heavy libraries are fetched on your first interaction rather than on page load, so reading a page costs nothing beyond the page itself.

Everything is designed against a strict performance budget: under 2.0s LCP on a 4G connection, under 150ms INP, and under 0.05 CLS. Every ad slot reserves its height before the ad exists, which is why the layout does not jump.

Is Expert Tools Kit really free?

Yes. Every tool, with no usage limit, no watermark and no account. The site is funded by banner advertising placed below each tool.

How can you offer this with no limits?

Because your device does the processing. Our costs are bandwidth for static files on a CDN, which is a tiny fraction of what running server-side conversion would cost.

Will you add accounts or a paid tier?

There are no plans to. An account system would require storing data about you, which is precisely what the architecture avoids.

Can I use these tools commercially?

Yes. There is no restriction on commercial use of the output. See the terms for the full detail.

Are the tools open source?

The underlying libraries are — pdf-lib, PDF.js, Tesseract and fflate are all MIT or Apache-2.0. The site implementation is not currently published.