Jsono JSON Viewer & Format

SHEMRAANGA

About this app

Jsono turns an unreadable line of JSON into something you can actually follow, and when a document is broken it tells you the line and the column rather than just that it failed.

Paste a response, open a file, or type it in. Format it with two spaces, four spaces or a tab. Collapse the parts you are not reading. Copy any value or its path. Minify it back to one line when you are done.

WHAT IS INSIDE

• Format — indent it, colour it by type, with line numbers
• Minify — one line, plus the same document escaped as a string for dropping inside another
• Tree — a collapsible view where a folded object keeps a chip saying how many keys are hidden
• Node — one value with its path, parent, index, depth, line and column
• Paths — every path in the document, filterable by key or value
• Shape — how many nodes, how deep, which types, the largest array, duplicate keys
• Validate — the exact line and column of the first error, with a caret and a suggested fix
• Mistakes — the eight that catch everyone, each shown wrong and then right

WHY IT HAS ITS OWN PARSER

Android ships a JSON parser, but it is lenient: it accepts trailing commas, single quotes and unquoted keys, so it cannot tell you a document is wrong, and it has no idea where anything sits in your file. Jsono uses a strict parser written for it, which follows RFC 8259 and tracks the line and column of every token. That is what lets an error have a position instead of just a message.

It also means key order is preserved exactly as written, and numbers are kept as the text you typed, so 1.0, 1e0 and 1 survive a round trip as three different documents instead of collapsing into one. Formatting changes whitespace and never changes a value. Duplicate keys are reported rather than silently resolved, because the grammar allows them and every parser picks a different winner.

NO ACCOUNT, NO NETWORK, NO PERMISSIONS

API responses often carry other people's data, so this one is worth being exact about. Jsono requests zero Android permissions, has no network code at all, and cannot browse your storage. A file reaches it only through the system document picker, which grants access to the single file you chose. Nothing you paste is written to disk unless you save it yourself.

No sign-in, no profile, no subscription, no in-app purchase, no advertising, no analytics.

WHAT IT WILL NOT DO

It will not fetch a URL for you. It will not accept JSON5 or JSONC — comments and trailing commas stay errors, deliberately. It will not validate against a schema, which is a different job. And it keeps no history of the documents you open.

Eight full-screen background themes are included under More. The interface is English throughout.