JSON1

JSON1 / About

Your JSON stays
on your machine.

JSON1 is 18 tools for reading, checking, and converting JSON. All of them run in the browser tab you are reading this in. That is not a policy decision anyone has to honour — there is no server to upload to.

What actually crosses the network

Every site says it respects your data. Here is the full list, including the parts that do not flatter us.

  • Your JSON0 bytes

    Parsing, formatting, and every conversion run in JavaScript on your machine. There is no API to send it to — the whole site is static files.

  • Page assetsonce

    HTML, CSS, JavaScript, and two fonts, all from this domain. After the first visit the browser caches them.

  • Google AdSenseon load

    An ad script, which sets cookies and reports the URL you are on. Like any script on a page it could read the DOM — we do not pass it anything, but that is our word, not a guarantee the browser enforces. Ads pay for the domain.

  • Analyticspage views

    Which pages get opened, and roughly where from. Never the editor contents, and there is no account to attach them to. Used to decide which converter to build next.

Do not take our word for any of it. Open your browser's network panel, paste a payload, and run a conversion — no request carrying it goes out. Or load a tool, switch to airplane mode, and keep working. If the last two rows bother you, an ad blocker removes them and every tool still runs.

By the numbers

18
Tools

One formatter, nine code generators, eight format converters.

4
Languages

English, 简体中文, Español, Português — full interface, not machine-translated labels.

0
Server round-trips per conversion

Turn off your network after the page loads. Everything still works.

Why build another one

Most JSON converters generate types from the first record in an array. That works until the second record has a field the first one lacked, at which point the generated interface is quietly wrong — and it is wrong exactly on the payloads where the type would have helped.

Every generator here reads all the records. A field present in some and not others comes out optional. A value that is sometimes null widens instead of guessing. Where the target language cannot express absence in a primitive, the boxed type is used, so a missing count does not silently become zero.

The claims in the notes under each tool are checked against real generator output rather than proofread. Three bugs were found that way, which is a reasonable argument for the practice.

Who maintains it

JSON1 is a small independent project, not a company with a sales team. It is free, needs no account, and stays that way. If a converter gets something wrong, the fix is worth more to us than the compliment — the tool notes exist because someone checked.