Who it is for

Developers and creators who need a quick, trustworthy utility — format a JSON payload, decode a URL, generate a UUID — without installing software or pasting data into an unknown server.

The problem it solves

Many online utilities upload whatever you paste, wrap it in heavy advertising, or require an account for a ten-second task. That is a real risk when the input is an API response, a token or customer data.

What you can do today

  • Developer utilities (73). JSON formatter, JSON/CSV/YAML/XML converters, SQL formatter, URL encoder and parser, Base64, Unix timestamp converter, crontab translator, text and JSON diff, JSONPath tester and more.
  • Security and hashing. MD5, SHA-1, SHA-256 and Keccak-256 hash generators, a password generator, and AES-256-GCM encrypt/decrypt that runs on the browser's Web Crypto API.
  • Algorithm visualisers (31). Step-by-step visualisations of sorting algorithms and data structures, including standalone sites such as sort-visualizer.zerethon.com and data-structures.zerethon.com.
  • Creator, maths and productivity tools. Open Graph preview, caption helpers, calculators and converters across creator (33), maths (19), productivity, science, writing and finance categories.
  • Guides alongside tools. Tool pages carry an explanation, examples and references, and a /learn hub groups explanations by topic.

How it works

  • Tools that only transform text (formatting, encoding, hashing, UUIDs, encryption) run in JavaScript in your browser, so the input is never sent to a Zerethon server.
  • Randomness comes from the browser's crypto.getRandomValues(), not Math.random() — this matters for UUIDs, passwords and encryption salts.
  • Pages load quickly and work in any modern browser, on desktop or phone — there is nothing to install.

Current limitations

Being clear about what a product doesn't do yet is part of describing it honestly.

  • Not every tool can be purely client-side — a tool that has to fetch a remote URL (such as an Open Graph preview) needs a server. Treat any online tool as unsuitable for secrets you are not allowed to handle on that device.
  • Browser-side tools are limited by the device: very large files can be slow or exhaust memory.
  • Tools are general-purpose helpers, not audited libraries — for production code, use a maintained library in your own stack.

Where to use it

tools.zerethon.com — free, no account needed. A companion browser extension launcher is open-source on GitHub.