JSON validator
Check whether JSON is valid and find the line and column of the first mistake. Free, with no account or uploads.
Paste JSON to check it
The first mistake is shown with its line and column. A repair is offered as a preview, never applied unasked.
More transformations
Sorting changes key order recursively, preserving array order. Repair can add or remove content; review its preview. Redaction matches exact property names, ignoring case, and does not guarantee every secret is removed.
Add valid JSON to explore its structure.
JSONPath: $.users[*].name, $..id, $.users[0:2], or $.users[?@.role == "editor"]. JSON Pointer: /users/0/id; ~1 means / and ~0 means ~. Values retain exact numeric text. Filters require safe numbers.
Object key order is ignored; arrays compare by position; numbers compare exactly. The patch transforms source into comparison, with at most 500 changes.
Add, remove, replace, move, copy and test are supported. Failures leave the source intact. Removing the root is rejected because it would leave no JSON document.
Draft-07, 2019-09 and 2020-12 (default). Email, URI and date-time format checks. Local $ref/$defs work; remote references are never fetched. No coercion, defaults or removed values. Up to 100,000 schema characters; operations stop after 20 seconds.
CSV/table view need an array of objects. CSV imports keep cells as strings. YAML aliases, merge keys, custom tags and non-string keys must be expanded or converted first. Types/schemas describe one sample and need review.
Source, comparison and schema text stay in this tab and clear on refresh. Files are not uploaded. The editor never runs pasted JavaScript. Cancel stops the worker without changing your source.
A little help along the way
Say what you want to do: make it readable (Edit, to format or repair), look through it (Explore), turn it into CSV or YAML (Convert) or compare two (Compare). The page says at once whether your JSON is valid. Under More options every workflow has its tab, with Query to select data and Schema to check a contract. Results stay separate until you choose Use result as source.
Questions people ask
- How do I find the error in my JSON?
- Paste it. The page says at once whether it is valid; when it is not, it gives the parser's own words with the line and column, and Go to error puts the cursor on that place.
- Can it fix broken JSON for me?
- Preview repair suggests a fixed copy (trailing commas, single quotes, missing commas and similar slips) in the result pane. It can guess wrong, so it is never applied until you choose Use result as source.
- Does it accept comments or trailing commas?
- No. It checks strict JSON as the standard defines it, so comments and trailing commas are reported as mistakes. Repair can take them out for you to review.
- Is the JSON I paste sent anywhere?
- No. It is checked in a worker inside this browser tab, nothing is uploaded, and the text is cleared when you refresh the page.
This page is the JSON formatter, opened for this one job; every other tool it has is one press away. Each of its settings is explained on the JSON formatter's own page.
Keep going
Guides
- Why is my JSON invalid? Common errors and how to fix them
- Is it safe to paste JSON into an online formatter?
- How to convert JSON to CSV and open it in Excel
- Convert CSV to JSON online without uploading it
- Compare two JSON files, ignoring key order
- JSON formatter and validator online, free, no login
- JSONPath tester online, with examples and JSON Pointer
- Repair broken JSON online, with a preview