JSON Viewer — See What Is Actually in the File

Open a JSON or JSONL file and see what is in it: a plain-English summary, a searchable tree, and errors with the exact line and column. Free, never uploaded.

Explained in plain English · errors with a line number · never uploaded

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JSON Viewer — See What Is Actually in the File

Most JSON tools indent the file and stop there, which helps only if you already know how to read it. This one starts by telling you what you are looking at, in plain English — “a list of 120 records; every record has id, name and email; some also have a phone number” — and then gives you the tools to dig in: a collapsible tree you can search, a formatted view you can copy, and the path to any value, ready to paste into code. If the file will not open, you get the line and column of the problem and the line itself, with the usual causes spelled out. JSON Lines files, which AI datasets and logs use and which a strict parser rejects, are recognised and read correctly. And because API responses and config exports so often contain keys and tokens, the file is read in your browser and never uploaded.

Explained in Plain English

A summary on top says what the file holds — how many records, which fields every record has, which only some do — before you read any brackets.

Errors With a Location

Invalid JSON shows the exact line and column, the offending line with a marker under it, and the usual causes in words.

Reads JSON Lines Too

One-record-per-line files from logs and AI datasets are recognised as JSONL instead of being reported as broken.

Never Uploaded

Config files and API dumps often hold secrets. This file is read in your browser and never sent anywhere.

!How It Works, Step by Step

Drop a .json or .jsonl file, or paste JSON into the box. Nothing is uploaded.

Read the summary at the top: it says what kind of data the file holds, in plain English.

Open branches in the tree, or search for a field or value; click any line to get its path.

Switch to Formatted to copy or download the file with clean indentation, or copy a minified version.

In Your Browser vs. on a Server

Feature	Local (Us)	Cloud Tool
Privacy	No upload (browser-only)	Pasted into a vendor page or API
Explains the data	Plain-English summary	Indentation only
Error location	Line, column and the line itself	Often just “invalid JSON”
JSON Lines	Recognised and read	Usually reported as an error

Technical FAQ

How do I open a JSON file?

Drop it onto this page or paste its contents into the box. The file is read by your browser, not uploaded, and shown three ways: a plain-English summary of what it contains, a tree you can expand and search, and a neatly indented version you can copy or download. You do not need to install anything or know how JSON works to read it.

What is a JSON file, in plain terms?

It is a text file that stores data in a structure programs can read. Two shapes do nearly all the work: a record, written in curly braces, which is a set of named values like a filled-in form; and a list, written in square brackets, which is several values in order. A typical data export is a list of records — think of it as a table where each record is a row and each field is a column.

Why does it say my JSON is invalid?

Because JSON is strict. The usual culprits are a missing comma between two items, an extra comma after the last one, text in single quotes instead of double quotes, and comments, which JSON does not allow at all. The viewer shows the line and column where parsing stopped and puts a marker under the character; the mistake is usually there or just before it.

What is a .jsonl file?

JSON Lines: one complete JSON value on each line instead of one value for the whole file. Logs, data exports and AI training datasets use it because a program can read or append one line at a time. A strict JSON parser rejects it at the first line break, so many viewers call a perfectly good file broken. This one recognises the format and shows the lines together as a list.

Is it safe to paste JSON that contains API keys?

Here, yes, because nothing leaves your browser — the parsing, the tree and the formatting all run in the tab. You cannot see whether an arbitrary site sends what you paste to a server, but you can check this one: open the Network tab in your developer tools and paste; no request carries your data.

How do I find a specific value in a large JSON file?

Type at least two characters into the search box above the tree. Every field name and value containing that text is highlighted, and the branches that contain matches open themselves. Click a result to see its path — for example users[3].email — which you can copy straight into code.

How large a file can it handle?

Files of tens of megabytes open, because the tree only draws the branches you open and pages long lists a hundred items at a time. Files over 2 MB are not shown in the editable text box, which becomes very slow at that size, but they are read in full and appear in the tree and the formatted view. The ceiling is your own device’s memory.

Keep the Work on Your Own Device

Every tool here runs in your browser, with no upload and no account. Here is another one worth knowing about.

Have a Markdown file instead?

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