Free Data Explorer
Data Explorer loads CSV, TSV, Excel, ODS, JSON, NDJSON, Parquet and SQLite files into an SQLite database on your device, where each file or sheet becomes a table and SQLite files keep every table. Sort, filter and search rows, run SQL queries and joins, build pivot tables and charts, then export to CSV, TSV, Excel, JSON, NDJSON or SQLite.
- Formats:
- CSV, Excel, JSON, Parquet, SQLite
- SQL engine:
- SQLite (sql.js, WebAssembly)
- Limit:
- Files up to 2 GB
- Price:
- Free
- Runs:
- Locally, in your browser
- Uploads:
- None: files never leave your device
- Account:
- Not needed
Quick answers
Are my files uploaded to a server?
No. The files are read by your browser and loaded into an SQLite database that runs on your device (WebAssembly in a background worker). Nothing is sent anywhere, and closing the tab discards everything.
How big can my files be?
CSV files of several hundred megabytes and millions of rows work on a typical computer, because the file is streamed into the database and the table only shows the rows you scroll to. The limit is your device's memory: plan for two to three times the file size. Files over 2 GB can't be opened in a browser tab.
Processed on your device: your files are never uploaded. How it works
Network activity in this tab
What this page has requested since you opened the site in this tab. An upload is any request that sends data: POST, PUT, PATCH or a request with a body.
No uploads: nothing has been sent from this page.
No network requests yet.
To see every request, open your browser's developer tools (Network tab).
How to use the Data Explorer
- Drop one or more files (CSV, TSV, Excel, ODS, JSON, NDJSON, Parquet or SQLite) or try the sample data. Each file becomes a table; nothing is uploaded.
- Browse the rows: click a header to sort, type in the boxes under the headers to filter (>10, 1..5, =Rome, null…) and use the search box; open Column stats for types, empty values, distinct counts, min, max and averages.
- Switch to SQL to query and join your tables with SQLite, or to Pivot and Chart to summarize the data without writing code.
- Export the table, the filtered view or a query result to CSV, Excel, JSON or NDJSON, or download everything as an SQLite database.
Credits & open source
Our own code plus open-source libraries. Thank you to the people who make these projects.
- sql.jsSQLite compiled to WebAssembly: runs SQL queries in the browser. © sql.js authors (Alon Zakai, Ophir Lojkine and contributors); SQLite is public domain · MIT
- Papa ParseRobust CSV parser. © Matthew Holt · MIT
- hyparquetPure JavaScript Apache Parquet reader. © Hyperparam (Kenny Daniel) · MIT
- ExcelJSReads and writes Excel .xlsx workbooks in the browser. © Guyon Roche and contributors · MIT
- fflateFast ZIP compression for batch downloads. © Arjun Barrett · MIT
- CodeMirror 6Code editor with syntax highlighting. © Marijn Haverbeke and others · MIT
- @uiw/react-codemirrorReact wrapper for CodeMirror 6. © Kenny Wong (uiwjs) · MIT
Web platform APIs used: Web Workers, WebAssembly, File API, localStorage, Clipboard API, Canvas 2D.
Full license texts: third-party notices · all credits
Frequently asked questions
Which SQL can I use?
SQLite's dialect: SELECT with JOIN, GROUP BY, window functions, common table expressions, date functions, JSON functions and more. You can also create tables and views, insert, update and delete. The last query result is available as _result.
Can I convert files, for example JSON to CSV or CSV to Excel?
Yes. Open the file and use Export: the table (or just the filtered and sorted rows) can be saved as CSV, TSV, Excel, JSON or JSON Lines. You can also download all tables together as one SQLite database.
Why do some numbers show up as text?
Column types are guessed from the data. Codes with leading zeros (like 007 or ZIP codes) are kept as text on purpose so they don't lose their zeros. Numbers written with thousands separators such as 1,234 are also text; you can convert them in SQL with REPLACE and CAST.
Can it open Parquet files?
Yes, Parquet files compressed with Snappy or Gzip (or uncompressed) are supported. Files that use ZSTD, Brotli or LZ4 compression can't be read yet.