ZTools

Most online tools ask for the file before they do anything with it.

You paste a document into a converter and it travels to a server you have never heard of, run by a company whose terms you did not read, and the copy left on their disk stops being your business the moment it lands. The file comes back. The transaction looks free.

Then the next task needs a different site.

By the end of an afternoon a working process has been assembled out of strangers, and not one of them told you what it kept.

ZTools inverts that. The work happens on your device unless there is a real reason it cannot, so for most of the toolbox the file never leaves the machine you opened it on.

That constraint costs something on the first day and pays for itself every day after. There is no upload endpoint to secure, no storage bill that grows with use, and no server that must be awake at three in the morning so that a JSON formatter works.

One person can keep it running.

20 categories, covering text, image, PDF, code, data, SEO, conversion, generators, math, finance and health. One React 19 and Vite 8 codebase produces three shipped things: the web app, an Android build on Google Play and a browser extension.

They ship at version parity 2.0.0, so a fix is a release on three surfaces rather than one.

Above the free core sits a BYOK AI suite of 10 SEO, AEO and GEO tools. You bring your own OpenAI, Gemini or Anthropic key. The request runs through a Cloudflare Worker on the free tier, which keeps the running cost at nothing.

A ZTools Pro tier is billed through Stripe. The whole product can be resold under another brand or licensed at source, with licence verification built into the application rather than promised in a contract.

ZTools is also where the prerendering approach the rest of this practice now uses began. 603 static HTML pages are generated at build time, so a tool page answers a crawler with its actual content instead of an empty document that promises to fill itself in later.

Then there are the costs, and they are the kind you only meet after launch.

Client-side processing means the device does the work. A large PDF on an old phone is slower than the same job on somebody else's hardware, and that trade is what the privacy claim is actually made of.

Version parity across three surfaces means three review paths for one fix. The extension goes through a store review. The Android build goes through another. The web deploys immediately, so for a while after a release the three are not honestly in step.

Bring-your-own-key is the fair way to run AI tools and it is friction. Somebody who wants that suite has to go and get a key before anything happens at all, and that friction is accepted on purpose.

There is no iOS build. There is no Apple Developer account behind this work, so nothing here has ever gone to the App Store and the page does not pretend otherwise.

The tools that must reach a server say so where you use them. The rest do not need one, and you can check that from the network tab in about ten seconds.