Turn JSON & CSV into beautiful tables.
View, explore and convert structured data directly in your browser. Free, private and no signup required.
Drop JSON, CSV or TSV here
Supports deeply nested JSON, custom delimiters, CRLF & multiline CSV
Fast, Private JSON & CSV Data Exploration
DataLens is designed specifically for developers, data analysts, and privacy-conscious users who need to view, inspect, transform, and export structured JSON, CSV, and TSV files without sending private data to cloud servers.
100% Client-Side Privacy
Your files and parsed datasets never leave your computer. All parsing happens inside your browser.
Instant Performance
Web Workers and virtualized table rendering ensure smooth scrolling for thousands of rows without browser lag.
No AI or Server Storage
Deterministic type inference, flattening, and formatting without non-deterministic AI or database backends.
Common Use Cases
- Inspecting deeply nested API payload responses
- Converting large CSV exports into Markdown tables for documentation
- Filtering and searching datasets without launching heavy desktop tools
- Flattening dot-notation object keys for flat tabular reporting
- Expanding array of objects into separate rows
- Validating CSV quoting, multiline fields, and custom delimiters
Frequently Asked Questions
Is my data uploaded to any server?
No. All file reading, parsing, schema inference, and export calculations take place 100% locally inside your web browser using HTML5 File APIs and Web Workers.
What is the maximum file size supported?
DataLens handles multi-megabyte datasets easily using background Web Workers and TanStack virtualized table rendering.
Can I convert nested JSON objects into flat CSV or Markdown?
Yes. Click on any nested object cell or use the Column Manager to flatten object properties into dot-notation columns (e.g. profile.location.city).
Is DataLens free to use?
Yes, 100% free with no registration required.