Why another tools site.

The existing ones work, mostly. They also weigh two megabytes, ask for an account to save a preference, and put a cookie dialog between you and a base64 decode. This is the correction.

The rules

• One job per tool. If it needs a mode switch to do something unrelated, it is two tools.
• Each tool is its own page at its own URL, not a route in an app.
• The pages themselves cannot make a network request. Not "do not" but cannot: every page carries connect-src 'none', so the browser refuses to let it contact anything, including this site. Paste a JWT and it stays in the tab.
• The one exception is the service worker, which downloads this site's own pages once so they keep working offline. It is allowed to talk to addabit.org and nowhere else, and it only ever fetches files that are part of the site.
• No accounts, no cookies, no analytics, no third-party anything. The fonts are served from this domain.
• Keyboard first: Ctrl+K anywhere, / to filter on the home page.
• Everything works without JavaScript enough to navigate; the tools themselves obviously need it.

Installing it

On a phone, the browser's share or menu button offers Add to Home Screen; on a desktop browser there is usually an install icon in the address bar. It then opens like any other app, full screen and with no browser chrome.

Installed or not, every tool keeps working with no connection at all: the whole site is about a megabyte and is stored on your device the first time you visit. That is the real reason for the size discipline: a tools site that needs signal is useless exactly when you are on a train.

What that costs

Doing everything client-side rules some things out. There is no URL shortener, no "fetch this page and analyse it", no server-side image conversion. Anything that needs a server is not here, and that is the trade this site is making on purpose.

It also means the heavy tools do real work in your tab. Hashing a 500 MB file will take a moment and use your CPU rather than someone else's.

Accuracy

Where a tool implements a specification, it follows the specification rather than an approximation: the QR encoder is ISO/IEC 18004 with proper mask scoring, the CRC variants are checked against the standard 123456789 vector, and the colour conversions use the reference OKLab matrices. Where something is an estimate, password entropy especially, the page says so plainly instead of showing a confident green bar.

Suggesting a tool

Tell me the job you were doing when you wanted it, not the tool you imagined: the job is the part I can actually design against. My contact details are on adabit.org.

Who made this

Made by ada. The rest of my work, and everything else I have written, is at adabit.org.

Running it yourself

It is a static site with no server component. Clone it, open dist/index.html, and every tool works from the filesystem, which is also the honest test of the no-network claim.