JSON Big ViewerPrivate JSON & NDJSON Viewer

Open large JSON files locally — no file upload required

Drop a JSON file here

JSON, NDJSON, and JSONL · processed locally in your browser

Tip: press Ctrl/⌘ + O to choose a file.

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Responsive Parsing

Background processing

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Virtual Tree View

Built for large files

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Files Stay Local

Processed in your browser

A private, browser-based viewer for large JSON and NDJSON files

Open, search, format, validate, and convert JSON locally in your browser. Your JSON content is not uploaded to our application servers.

How It Works

1

Open a File or Paste JSON

Choose a JSON, NDJSON, JSONL, or text file, or paste JSON directly into the browser.

2

Browse the Tree

Expand and collapse nested values to inspect your data without losing your place.

3

Search, Format, and Validate

Find keys or values, format or minify valid JSON, and check syntax before sharing data.

4

Copy or Export

Copy formatted JSON, download data, or convert compatible structures to CSV, SQL, TypeScript, and JSON Schema.

Features

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Background Processing

Parsing runs in a Web Worker to help keep the interface responsive while files are processed.

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Virtual Tree View

Browse complex JSON in an expandable tree designed to avoid rendering unnecessary rows.

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Full-Text Search

Find keys and values, then move through highlighted matches without losing context.

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Format Conversion

Convert compatible JSON to CSV, SQL, TypeScript interfaces, or JSON Schema in your browser.

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NDJSON and JSONL

Open newline-delimited JSON files and export selected objects when you need a smaller subset.

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JSON Stays Local

Your JSON content is processed in your browser and is not uploaded to our application servers.

Why Use JSON Big Viewer

Built to Stay Responsive

Web Worker parsing and virtual tree rendering help keep navigation responsive while you inspect large structures.

Your JSON Stays Local

Your JSON content is processed in the browser and is not uploaded to our application servers. See the Privacy Policy for analytics details.

Practical Large-File Support

Use it with files over 100 MB when your device has sufficient memory. Actual limits depend on your browser and file structure.

Free, No Account Required

Use the viewer without creating an account or entering payment details.

Useful Export Options

Convert compatible structures to CSV, SQL, TypeScript, or JSON Schema when you need to continue work elsewhere.

Frequently Asked Questions

How large can a file be?▼
JSON Big Viewer is designed for large files, including files over 100 MB. The practical limit depends on your browser, available memory, device, and file structure. For large files, use an up-to-date desktop version of Chrome or Firefox.
Is my JSON data uploaded to a server?▼
No. JSON file contents and pasted JSON are processed locally in your browser and are not uploaded to our application servers. We use Google Analytics for aggregate site measurement; see our Privacy Policy for details.
Can I convert JSON to CSV or SQL?▼
Yes. JSON Big Viewer can convert compatible JSON objects or arrays to CSV, SQL (CREATE TABLE plus INSERT statements), TypeScript interfaces, and JSON Schema. Conversions run locally in your browser.
What is NDJSON and how do I view it?▼
NDJSON (Newline Delimited JSON) stores one JSON object per line. Upload a .ndjson or .jsonl file and JSON Big Viewer will parse the valid objects so you can browse or export them.
Is JSON Big Viewer free to use?▼
Yes. JSON Big Viewer is free to use and does not require an account.
Which browsers are supported?▼
JSON Big Viewer works in modern browsers with Web Worker support, including Chrome, Firefox, Safari, and Edge. For large files, we recommend the latest desktop Chrome or Firefox.

Your JSON content is processed locally in your browser and is not uploaded to our application servers. We use Google Analytics to understand aggregate site usage, as described in our Privacy Policy.

Ready to open a JSON file