Paste JSON on the left, drop a .json file anywhere,
or start from an example.
Everything runs in your browser. No data ever leaves your device.
Paste a raw API response, a package.json, a GeoJSON export or a
1 MB log payload and read it in seconds. This online JSON viewer
beautifies unreadable one-line JSON, flags syntax errors with the exact line and
column, and renders the result as a collapsible tree you can search, filter and
copy paths from.
Everything runs as JavaScript inside your own browser. There is no upload, no server round-trip, no account and no advertising — which also means the tool stays usable for API keys, customer records and other data you should never paste into a third-party service.
One page replaces the half-dozen single-purpose JSON utilities you normally keep bookmarked.
Re-indent minified JSON with 2 spaces, 4 spaces or a tab, with full syntax colouring for keys, strings, numbers, booleans and null.
Validation runs while you type. Invalid JSON shows the parser's message plus the failing line and column, so you fix the trailing comma instead of hunting for it.
Expand and collapse objects and arrays, see child counts at a glance, and walk the whole structure with the arrow keys.
Type in the filter box to keep only the branches whose keys or values match, with every hit highlighted and counted.
Strip every optional space and newline to shrink a payload before you ship it over the wire or paste it into an environment variable.
Click a key to copy its path — $.users[0].email — ready to drop into a test, a jq expression or a bug report.
Open .json, .geojson, .map or .txt files from disk, or drop them anywhere on the page.
Point the viewer at a REST endpoint and inspect the response directly, without leaving the browser or installing an API client.
Normalise key order while formatting so two config files can be diffed line by line.
.json file onto
the page, or fetch it straight from a URL with the Load URL button.
.json file.
Most free JSON formatters POST your text to their backend to render it. That is fine for a toy payload and a genuine problem for anything else: production API responses routinely carry bearer tokens, e-mail addresses, order histories and internal IDs. Once that text reaches someone else's server you have no way to know whether it was logged.
This viewer never makes that request. The parser, the formatter, the minifier and the tree renderer are plain JavaScript files served once and executed locally, so you can confirm the behaviour yourself with the Network tab open. Load the page, go offline, and everything still works.
| Typical online JSON formatter | This JSON viewer |
|---|---|
| Sends your JSON to a server to process | Parses it in your browser |
| Ad banners and cookie consent walls | No ads, no trackers, no cookies |
| Sign-up required for larger files | No account, ~25 MB files |
| Breaks without a connection | Works fully offline |
| Output is a plain text box | Searchable, collapsible tree with JSONPath |
Both operations produce exactly the same data — only the whitespace between tokens changes. Beautifying (also called prettifying or formatting) is for humans reading the structure. Minifying is for machines moving bytes.
{"id":42,"name":"Ada","tags":["math","code"],"active":true}{
"id": 42,
"name": "Ada",
"tags": [
"math",
"code"
],
"active": true
}A rule of thumb: beautify while you debug, minify before you transmit. Whitespace can be a meaningful share of a small API response, and gzip does not fully erase the difference.
JSON is far stricter than JavaScript object literals, which is where nearly every parse failure comes from. These are the ones the validator reports most often.
| Error message | Cause | Fix |
|---|---|---|
Unexpected token } |
A trailing comma after the last item | Remove the comma before } or ] |
Unexpected token ' |
Single-quoted strings or keys | JSON only allows double quotes: "key" |
Unexpected token n |
A raw newline inside a string | Escape it as \n |
Unexpected end of JSON input |
A truncated payload or missing closing brace | Check the response was fully received |
Unexpected token N |
NaN, Infinity or undefined |
Use null, or a string |
Bad escaped character |
A lone backslash in a Windows path | Double it: "C:\\Users" |
Unexpected token / |
Comments — // or /* */ |
Strict JSON has no comments; strip them |
JSON (JavaScript Object Notation) is a text format defined by RFC 8259. It has exactly six value types and no more.
| Type | Example | Notes |
|---|---|---|
| Object | {"a": 1} | Unordered key/value pairs; keys must be double-quoted strings |
| Array | [1, 2, 3] | Ordered list; may mix types |
| String | "hello" | Double quotes only; \" \\ \/ \b \f \n \r \t \uXXXX escapes |
| Number | -3.14e2 | No leading +, no hex, no NaN or Infinity |
| Boolean | true | Lowercase only |
| Null | null | Lowercase only |
undefined, functions, or JavaScript expressionsjq.| Shortcut | Action |
|---|---|
Ctrl + Enter | Format / prettify |
Ctrl + Shift + Enter | Minify / compact |
Ctrl + F | Jump to the tree filter |
Ctrl + S | Download as .json |
Alt + C | Copy JSON |
Alt + L | Clear the editor |
Yes. Every feature is free and unlimited. There is no account, no paywall, no ads and no daily limit on how much JSON you can format or validate.
No. Parsing, formatting, validating and minifying all happen in your browser with JavaScript. Your JSON never leaves your device, which makes the tool safe for API responses, config files, tokens and other confidential payloads.
Paste your JSON into the left panel and press Format, or use the keyboard shortcut Ctrl+Enter. Choose 2 spaces, 4 spaces or tab indentation first if you want a specific style.
Validation is continuous — as you type, the status pill shows Valid or Invalid. When the JSON is malformed the error panel reports the reason plus the exact line and column, and the offending line is highlighted in the editor.
Beautifying (also called prettifying or formatting) adds indentation and line breaks so a human can read the structure. Minifying removes every optional space and newline to make the payload as small as possible for transport. Both produce the same data.
Files up to about 25 MB open comfortably on a modern desktop browser. Because the work is done locally, the real limit is your device's memory rather than an upload quota.
Yes. The page is a small static site with no external dependencies, so once it is loaded you can keep formatting JSON with no network connection. You can also install it as a progressive web app.
Yes. Use the Open file button, or simply drag and drop a .json, .geojson, .map or .txt file anywhere onto the page. The file is read locally by the browser.
Yes. Click Load URL and paste an endpoint. The request is made directly from your browser, so the server must send an Access-Control-Allow-Origin header. If it does not, download the response and open the file instead.
Click any key in the tree to copy its JSONPath, for example $.users[0].email. Clicking a value copies the value itself. The current path is always shown in the status bar under the tree.
Yes. The layout stacks the input and tree panels vertically on phones and tablets, and every action is available from the toolbar.
Any current version of Chrome, Edge, Firefox, Safari, Opera or Brave, on desktop and mobile. No plugin or extension is required.
The request is made straight from your browser, so the server must allow
cross-origin access (Access-Control-Allow-Origin). If it does not,
download the file and open it instead.
| CtrlEnter | Format / prettify |
| CtrlShiftEnter | Minify / compact |
| CtrlS | Download .json |
| CtrlF | Jump to the tree filter |
| AltC | Copy JSON |
| AltL | Clear editor |
| CtrlZ | Undo (format & clear are undoable) |
| Esc | Close dialog / clear filter |
| ↑↓→← | Walk the tree (when it has focus) |
.json file onto the page to open it.localStorage, so a refresh never loses it.