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.
Which Tool for Which Job
Eight tools, and the verb you are reaching for picks one of them. Name what you are doing to the text and the choice is already made.
- Format and inspect. The JSON formatter and validator beautifies at 2 spaces, 4 spaces or tabs, minifies back down, validates without touching your text, and can sort keys alphabetically all the way down the tree. Two things make it worth keeping in a tab: on a parse failure it reports the line, the column and a caret under the offending character whenever the browser hands over a position (Chrome and Firefox do; Safari sometimes gives only the message), and on success it summarises the payload — top-level type, total keys and array items counted recursively, maximum nesting depth, and the byte size. That last row answers “is this actually the shape I think it is?” faster than reading it.
- Convert. Two different senses of the word. Case converter handles text style — ten of them, from UPPERCASE and Sentence case through camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE — splitting on camelCase boundaries so an identifier converts correctly rather than collapsing into one word, with an Undo that restores the previous version. Roman numeral converter handles numbers, live in both directions at once, covering 1 to 3,999,999: above 3,999 it switches to vinculum notation with the historic overline and hands you a copyable plain-text form of it.
- Generate. The password generator draws from the browser’s cryptographic random source using rejection sampling, so no character is slightly likelier than another, and then shuffles the result so the characters it had to include do not land in fixed positions. Length runs 4 to 128, and the crack-time line assumes an offline rig at ten billion guesses a second. The UUID generator batches v4 IDs in whichever shape your column wants — uppercase, hyphen-free, or canonical — then copies the lot or downloads it as a file.
- Count and measure. The word and character counter is the one to keep open while writing to a limit: words, characters with and without spaces, sentences, paragraphs, and separate reading and speaking estimates, plus a keyword panel that strips out common function words so the ranking shows your own vocabulary rather than the word “the”.
- Strip, before you paste somewhere else. The text anonymizer is the one to reach for before a work document goes into a chatbot. Ten automatic detectors — emails, phone numbers, SSNs, card numbers, IP addresses, URLs, API keys, IBANs, @handles and likely first names — plus your own watch list of names it could not guess. You review every hit in context and keep or skip each one, and the replacements are numbered tags such as [EMAIL-1], so pasting the reply back into the restore panel puts the real values back where they belong.
- None of the above. The pomodoro timer with rain sounds is here because it is what you keep in the other tab: 25/5, 50/10 or 90/20, with rain, brown noise or white noise built live in the browser (the rain is filtered noise with a slow drift on the cutoff, which is why it never loops) and silence on your breaks.
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 pinpoints a syntax error as precisely as your browser reports it, down to a code-frame caret under the offending character; the password generator guarantees every character set you select actually appears and tells you how long it would take to crack; 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.
What Each Tool Keeps, and What It Deliberately Forgets
These tools do not share one persistence rule, and the differences are on purpose. The JSON formatter keeps your input along with your indent and sort settings; the word counter and the case converter each keep your text. All three put a one-click clear beside the input for the times you would rather they did not.
The password generator and the UUID generator keep nothing at all — not the output, not even your options. Reload either one and you are back at the defaults, because a generated secret sitting in local storage is a secret written to disk. The anonymizer is stricter still, and deliberately stricter than the other text tools: your watch list and your detector settings persist, but neither the text you scanned nor the tag-to-original mapping is stored unless you switch on remembering the mapping. An anonymizer that quietly kept raw sensitive text would be breaking its own promise.
The precise version of the privacy claim, since it is the reason most people are here: the transforms themselves make no network call. Formatting, converting, counting, generating and detecting all run as ordinary functions on your machine, and there is no endpoint on this site that accepts the content you paste into a tool. Three things on a tool page do transmit, though, and you should know all three. The feedback box sends what you write in it, deliberately, because that is how a request reaches whoever builds these. Each page view fires one anonymous counter ping with the path you are on and the referrer you arrived from, of which the server keeps only the domain. And clicking one of the related-tool links posts that click — which link, from which page — so the suggestions can be ordered by what people actually open. None of the three carries a cookie, an identifier for you, or a character of what you pasted. The feedback send is the one worth opening in full, because it carries more than your message: the page you sent it from, your thumbs up or down, an email address if you filled that field in, an empty honeypot field, and the one-time bot-check token from the box you just opened. No advertising script runs on these pages right now. One third party can still turn up, and it is worth naming: opening the feedback box loads a Cloudflare Turnstile bot check from challenges.cloudflare.com. Leave that box shut and what the network tab shows you while you work is the page-view ping, any related-tool click, and the ordinary business of loading a page.