Does this site store the JSON I paste?

No. Parsing, conversion and hashing all happen in your browser memory, and there is no backend endpoint that receives them. The only exceptions are local to your own device: the most recent input is kept in session storage so that a page refresh does not lose it, and a few interface preferences (the light or dark theme, and whether you dismissed the language suggestion) are kept in local storage. Clearing your browser data, using a private window, or pressing Clear inside a tool removes all of it.

Is there a free plan, or anything that needs an account?

There is no paid tier and no account. Every tool is available without usage limits, nothing is locked behind a login, and there is nothing to sign up for. The running costs of the site are covered by the ads shown on the page.

Why are some converters one-way only?

Some conversions lose information by nature. Converting JSON to CSV, for example, flattens nested structures into text inside cells, and converting back cannot distinguish a string that merely looks like an object from a genuinely nested one. Those tools state the one-way limit instead of returning output that runs without complaint but quietly changes the data.

What should I do if a tool gives a wrong result?

Results are expected to match the formal specification of the language or format involved — JSON permits double-quoted strings only, and NaN is not a valid JSON value, to take two examples. If a result disagrees with the specification, or with a reference implementation, please report it; that kind of report is handled first. Suggestions for tools that are missing are welcome as well.

About this site: developer tools that run entirely in your browser

What this site is, how it is built, and why every tool runs entirely inside your browser.

This site is a set of online tools for developers, built around JSON and extended to cover the encoding, conversion, regex and timestamp chores that come up constantly in day-to-day work. There is no account to create, nothing to install, and no sign-up wall between you and a working tool.

The one thing worth stating before anything else: every calculation happens inside your browser, and what you type is never sent to a server. That is not a marketing line here, it is the technical premise of the site — no backend endpoint, no database, and no code path anywhere in the project that uploads the contents of an editor.

Why every tool runs in your browser

The data a developer needs a tool for tends to be exactly the data that must not leave the machine: production API responses, database exports containing real user records, configuration that has not been redacted yet, request bodies carrying live tokens. Pasting that into an unfamiliar site and having a server log it is a failure mode that has occurred in practice, more than once. So this site takes the plainer route. All parsing, conversion, hashing and validation logic ships as static files and executes in the page, which means the data has no exit to take. You can verify that rather than take it on trust: disconnect from the network, keep using an already-open page, and everything still works — if the tools depended on a server, they would fail the moment the connection dropped.

Where the tools come from, and how they hand off to each other

Each tool started from a specific, recurring annoyance rather than a feature list. A minified API response that has to be expanded before its shape is visible at all. A documented example that no longer matches the real payload, so fields have to be compared layer by layer. Turning a JSON sample into a typed struct by hand, one field at a time. Chasing a timestamp that might be seconds or milliseconds and trying both. None of these is hard on its own, but each one costs a detour: find a tool, paste the data in, and hope it is not being kept somewhere. Because the tools sit together, they also work in sequence: what you paste into the formatter is still there when you open the diff view, the tree view, the JSONPath query or a code converter, so the same payload never has to be pasted twice. In practice the flow is paste once, then do whatever the data needs — validate it, compare two versions, query it, turn it into types — without losing your place or your input along the way.

How the site is built, and what pays for it

This is a static site. Every tool page is prerendered into its own HTML file at build time, so each tool has an address search engines can index on its own, and the page opens without waiting for a script bundle to arrive and boot. Editors use Monaco, the same core as VS Code, which brings real syntax highlighting, error locations and side-by-side diffs. There is no account system and no collection of what you type. Domain and hosting costs are covered by display ads, and ads never change how a tool behaves; the privacy policy explains what those ads may set in your browser.

What a browser-only site cannot do

The limits of this design are real, and naming them is better than pretending otherwise. Anything that requires a server — sending live HTTP requests, looking up IP geolocation, converting documents that need a rendering engine, calling an API that requires a secret key, storing or sharing a snippet at a URL — is deliberately out of scope. The alternative would be to send your input somewhere, which is precisely what this site refuses to do, or to fake the result in the browser, which is worse than not offering the tool at all. So those tools are simply absent, and the ones that do exist are honest about their own boundaries: conversions that lose information say so, and results follow the formal specification of the format being processed rather than an approximation of it.

Frequently asked questions

Does this site store the JSON I paste?: No. Parsing, conversion and hashing all happen in your browser memory, and there is no backend endpoint that receives them. The only exceptions are local to your own device: the most recent input is kept in session storage so that a page refresh does not lose it, and a few interface preferences (the light or dark theme, and whether you dismissed the language suggestion) are kept in local storage. Clearing your browser data, using a private window, or pressing Clear inside a tool removes all of it.
Is there a free plan, or anything that needs an account?: There is no paid tier and no account. Every tool is available without usage limits, nothing is locked behind a login, and there is nothing to sign up for. The running costs of the site are covered by the ads shown on the page.
Why are some converters one-way only?: Some conversions lose information by nature. Converting JSON to CSV, for example, flattens nested structures into text inside cells, and converting back cannot distinguish a string that merely looks like an object from a genuinely nested one. Those tools state the one-way limit instead of returning output that runs without complaint but quietly changes the data.
What should I do if a tool gives a wrong result?: Results are expected to match the formal specification of the language or format involved — JSON permits double-quoted strings only, and NaN is not a valid JSON value, to take two examples. If a result disagrees with the specification, or with a reference implementation, please report it; that kind of report is handled first. Suggestions for tools that are missing are welcome as well.