Free tool · JSON viewer online
Free JSON viewer
Paste JSON or drop a .json file to format, validate and explore it as a tree. Errors point to the exact line and column. When it reads right, publish it as a shareable link.
How it works
Format and explore JSON in three steps
Paste or drop
Paste JSON into the editor, or drop a .json file. It is parsed as you type, and invalid JSON shows the line and column of the first error.
Explore the structure
Open and close branches in the tree, with item counts on every array and object, or switch to the formatted view for the whole document.
Format, copy, or publish
Pretty-print with a 2-space indent or minify to one line, copy the result, or publish the formatted JSON as a page you can send as a link.
Where JSON comes from
A JSON formatter for the JSON you get handed
AI output
Claude and ChatGPT return structured data as long JSON blocks, sometimes with a missing comma or a trailing one. Check it here before it goes into your code.
API responses
Webhook payloads, REST responses and log lines arrive minified on one line. Paste them in to read the fields, find a nested value, and count the items.
Config files
package.json, tsconfig, app settings and exported data: open the file to confirm it parses, and spot the bracket that went missing in a hand edit.
The next step
Share a formatted JSON as a page
Noindex by default
Published pages tell search engines to stay away, so a shared payload won’t surface on Google the way most free paste sites can.
Password protection
Lock pages that hold customer data with an encrypted password we can’t read, enforced before the page ever loads.
View tracking
See opens, unique viewers, country, referrer, and time on page, so you know the developer on the other side actually looked.
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Yes. The JSON is parsed and formatted by your own browser. Nothing you paste or drop is uploaded, stored, or logged, so API keys, customer records and tokens stay on your device. It only leaves if you choose to publish it as a page.
Files of several megabytes work, limited only by your device’s memory. Above 2 MB the tree view switches off, because thousands of expandable nodes would slow the page down, but the formatter still pretty-prints, minifies and validates the whole file.
Yes. Every edit is checked against the JSON standard. Valid input shows its size, key count and depth; invalid input shows the line and column of the first problem with a plain reason, such as a trailing comma, a missing quote, or single quotes where JSON needs double ones.
Yes. Copy it, or use Publish to turn the pretty-printed JSON into a page with its own link. The page is noindex by default, and on a paid plan you can add a password and see who opened it.
Open this page in your phone’s browser, tap Upload file, and pick the .json file from your downloads or files app. It opens in the tree view, where you tap a branch to expand it, which reads far better on a small screen than a wall of raw text.