Topic Hubs

JSON tools read, check and reshape JSON data. This set covers the four jobs that come up most: making JSON readable, proving it is syntactically valid, comparing two versions of a document, and converting between JSON and other data formats.

Image optimisation is the practice of making an image file smaller without making it look worse. In practice that means three separate operations — compress, resize, convert — and picking the right one first is what stops you degrading a photo you did not need to touch.

PDF is a final-output format, so most PDF work is conversion in one direction or the other: getting content *into* a PDF, getting it back *out* into something editable, or reorganising pages inside a file you already have.

Text transformation tools normalise messy input — the invisible characters, inconsistent spacing and duplicated lines that come from copying between editors, CMS platforms and PDFs — and reshape text for a specific destination.

These tools cover the machine-readable layer of a page: the tags that tell search engines and social platforms what it is, and the files that control whether they are allowed to read it. Get them wrong and a page either renders badly in a share card or never gets indexed at all.

Password and security tools handle secrets, which makes where they run the whole point. Everything on this hub computes locally in your browser — no password, hash input or token is ever transmitted or logged.

Colour and CSS generators turn a visual decision into code you can paste. The workflow is usually the same: choose or sample a colour, check it is accessible, then generate the CSS for the component you are building.

Time tools split into two jobs that are easy to confuse: measuring time (clocks, timers, stopwatches) and computing with dates (differences, deadlines, timestamps, business days). Knowing which one you need saves a lot of fiddling.

AI writing tools help at three different moments: improving text you already wrote, producing a first draft you will edit, and finishing the last mile on work you would otherwise put off. The tool matters less than knowing which of those three jobs you are doing.

A calculator is only useful if you trust the number it returns, so each of these shows the formula or method it uses. Results are estimates for general information — they are not financial or medical advice.

A formatter rewrites code with consistent indentation so a human can read it; a minifier removes every byte a machine does not need so it downloads faster. They are opposites, and mixing them up is the most common mistake — minifying code you are about to debug, or shipping formatted code to production.

Encoding converts data between representations so it survives transport — it is not security. Base64 makes binary safe for text channels, percent-encoding makes a value safe inside a URL, HTML entities make characters safe in markup, and ciphers like Caesar or Morse are historical encodings with no confidentiality left.

A creator publishes one piece of content four ways — the video, the thumbnail, the caption and the hashtags — and each has its own size and format rules. These tools cover that loop end to end: grab the asset, shape it to the platform, write the copy, style the text.

A QR code or barcode is a link printed into the physical world, so the job splits in two: encoding something into a code that scans reliably, and reading a code back into data. Generation is forgiving; scanning depends on the camera plus the code’s size and contrast.

Browser games run completely on your device using HTML5 Canvas and WebAssembly. No downloads, installations, accounts, or pop-up ads interrupt your session — jump in for a quick 2-minute break or play multiplayer with friends.

Personal tracking tools help you build steady daily habits — from budgeting and splitting group bills to daily hydration, mental wellness, and reflection. All personal data is saved strictly to your browser local storage with zero server uploads.