lans.cloud

Free Developer & Text Tools — No Sign-Up

Everything below runs entirely in your browser: format JSON, generate passwords and UUIDs, convert cases, count words. Nothing you paste is ever uploaded, and there are no accounts.

Case Converter

Free text case converter: UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case, kebab-case and more — instantly in your browser.

UUID Generator

Free UUID v4 generator. Create one or up to 500 random UUIDs with uppercase and no-hyphen options, generated locally with cryptographic randomness.

Roman Numeral Converter

Free Roman numeral converter. Convert numbers 1–3999 to Roman numerals and back, live in both directions, with strict validation.

Word & Character Counter

Free word counter and character counter. Live counts for words, characters, sentences, paragraphs, and estimated reading time as you type or paste.

Password Generator

Free secure password generator. Create strong random passwords with custom length and character sets, generated locally with cryptographic randomness.

Pomodoro Timer with Rain Sounds

Free pomodoro timer with rain and brown noise generated live in your browser — no audio files, no loop seams. Classic 25/5 and deep-work presets, chimes, daily counter, ad-free fullscreen.

JSON Formatter & Validator

Free online JSON formatter and validator. Beautify, minify, and validate JSON instantly with exact error locations — private, in your browser.

Your Data Never Leaves the Browser

Most online formatters and generators send whatever you paste to a server, process it there, and send the result back. That is a problem the moment your JSON contains an API key, your text is an unreleased draft, or the password is one you will actually use. Every tool on this page works the other way: the parsing, generating, and converting all happen in JavaScript on your own machine. Open the network tab while you work — you will see no requests carrying your data, because there is no endpoint to send it to.

Small Tools That Respect Repeated Use

These are tools you reach for twenty times a day, so they are built for that rhythm: your draft and settings persist in local storage between visits, results copy with one click, and there is nothing to log into or dismiss first. The JSON formatter points at the exact line and column of a syntax error with a code-frame caret; the password generator guarantees every character set you select actually appears and shows the entropy in bits; the UUID generator produces up to 500 crypto-random v4 IDs in the format your codebase expects.

Start With These Three

If you are new here: the JSON formatter & validator is the workhorse (format, minify, sort keys, and find the error line in malformed payloads), the password generator covers everything from quick throwaways to 128-character vault entries, and the case converter translates between camelCase, snake_case, kebab-case, and seven other styles with proper word-boundary detection. For focus while you work, the pomodoro timer with rain sounds synthesizes its soundscapes in the browser — no audio files, no streaming.

Frequently Asked Questions

Is my text or JSON uploaded to a server?

No. Every tool on this page runs entirely in your browser — the JSON you format, the text you count, and the passwords you generate never leave your device. There is no server code that could receive them, which you can verify yourself in the browser network tab.

Are these developer tools really free? Do I need an account?

Fully free, no accounts, no premium tier, no locked features. The pages carry clearly separated ads — that is what pays the hosting — but the tools themselves are never limited.

Is the password generator safe to use for real passwords?

Yes: it uses the browser’s crypto.getRandomValues (a cryptographically secure random source, not Math.random), generates everything on your device, and shows the entropy in bits so you can judge strength. Nothing is transmitted or stored.

Do the tools keep my work if I close the tab?

Most of them save your latest input and settings in your own browser’s local storage — the JSON formatter keeps your draft, the word counter keeps your text, the case converter remembers your last conversion. Clearing browser data removes it; nothing is stored anywhere else.

Do they work offline?

Mostly yes: because everything computes in your browser, an open tool keeps working if your connection drops. Loading or reloading a page needs a connection.