Developer tools
Utilities for the files developers handle all day — currently JSON. They run entirely in your browser, so an API response full of tokens or customer records never has to be pasted into someone else's server to be tidied up.
All developer tools
Why a formatter should run locally
The JSON you want to read is rarely public. It is a webhook payload with a signing secret in it, a config export with database credentials, a log line containing an email address. Most online formatters post that text to a server to pretty-print it, and their privacy policies are the only thing standing between your paste and their logs. The JSON Formatter here parses with your browser’s own JSON.parse, so the text never leaves the page. You can watch the network tab stay empty while you work.
Formatting and validating are the same operation: the parser either accepts the text and reformats it, or rejects it and reports where. The tool turns the engine’s message into a line and column, which is usually all you need. For the cases a parser can’t catch — duplicate keys, integers too large to survive a round trip — read Why is my JSON invalid?.
One tool, on purpose
This shelf holds a single tool because that is what exists and works. Tools are added when they can run fully in the browser and solve a job people actually bring us — not to fill a category. If there is a data-file task you keep reaching for a random website to do, tell us. Meanwhile, the PDF to Text extractor under PDF tools is the other utility developers tend to want.