Paste several JSON snippets at once — separated by a divider line — and validate and pretty-print every one in a single pass. No file upload: just paste text copied from an API response, a config block, a log line, or a Slack message.
Paste one or more JSON snippets. Separate multiple snippets with a line containing just -----. Optionally start a snippet's block with ### name to label it in the results.
Each snippet is run through the browser's own JSON.parse — the same parser your JavaScript code, your build tooling, and most API clients rely on. A snippet either parses cleanly (in which case it's re-serialized with your chosen indent so you get a pretty-printed copy) or it doesn't, in which case you get the parser's own error message plus the line and column it points to, when the browser's error message includes one. This is a well-formedness check, not JSON Schema validation — it confirms the syntax is valid JSON, not that specific fields or types match a schema you have in mind.
API responses, config blocks, and log lines rarely arrive as a single tidy object — a debugging session usually means several snippets copied from different places (a request body here, a response there, a Slack thread with three broken payloads someone's asking about). Checking each one separately means re-opening the tool and re-pasting every time. Pasting a batch at once, with each one labeled, keeps the whole set in view together and makes it obvious at a glance which specific one is broken.
Most "batch JSON" tools online are built around uploading files — pick or drag several .json files, then process them. That's the right fit when you actually have files on disk. It's the wrong fit when what you have is a block of text you just copied from a browser's network tab, an API playground, or a chat message — you'd have to save it as a file first just to use the tool. This one skips that step entirely: paste text directly, separated by a divider, and nothing is written to disk or uploaded anywhere to do it.
The most frequent ones by far: a trailing comma after the last item in an object or array (valid in JavaScript object literals, never valid in JSON), single-quoted strings instead of double quotes, unquoted object keys (also fine in JS, not in JSON), and a missing comma between two properties or array items. All four are easy to introduce when copying a JavaScript object literal and assuming it's already valid JSON — it usually isn't. See this post for the full list, including two cases (comments and duplicate keys) that don't always throw the error you'd expect.
No — this checks that each snippet is well-formed JSON (the syntax parses correctly), not that it matches a particular schema of required fields and types. If you need schema validation, this tool isn't the right fit; it's aimed at the much more common everyday problem of "why won't this parse."
The exact wording of a JSON.parse error — and whether it includes a position at all — is decided by your browser's JavaScript engine, not by this tool, and it varies between browsers. When the error message includes a position, this tool shows the exact line, column, and a short excerpt with a caret pointing at the problem. When it doesn't, you still get the parser's own error text, just without the extra location detail.
No hard limit is enforced — paste as many divider-separated snippets as you need. Since everything runs in your browser with no server round-trip, the practical ceiling is your device's memory for very large batches, not anything this tool restricts.
No — parsing, formatting, and error detection all happen locally in your browser using the built-in JSON.parse and JSON.stringify. Nothing you paste here is uploaded or stored on a server. See this post for the fuller difference between browser-only and upload-based JSON tools.