Documentation

Learn JSONFiddle by workflow

Short guides for viewing, querying, editing, converting, and exporting structured data in the browser.

SQL on JSON

SQL on JSON lets you run DuckDB queries against JSON and CSV data directly in the browser. It is useful when a payload is too large or too tabular for Graph or Explorer, or when you need joins, grouping, filtering, and aggregation.


When to Use SQL

Use SQL when you need to:

  • Query a large array without expanding every nested branch.
  • Compare multiple editor tabs as tables.
  • Add temporary JSON or CSV data sources.
  • Group, count, aggregate, join, or export query results.
  • Keep an analysis query separate from the source payload.

SQL is still browser-first. The query engine runs locally through DuckDB WASM.


Add Data Sources

Open Tools > SQL on JSON or switch to SQL from the workbench tools menu.

You can add sources in three ways:

  1. Open JSON or CSV tabs in the editor.
  2. Click Add JSON in the SQL data source panel.
  3. Import a file as a table source.

Each source appears in the left panel with row and column counts. The generated table name is safe for SQL and can be used in queries immediately.

SELECT *
FROM orders
LIMIT 100;

Query Examples

Filter rows

SELECT *
FROM orders
WHERE status = 'delivered';

Count rows

SELECT COUNT(*) AS total_rows
FROM orders;

Group and sort

SELECT status, COUNT(*) AS count
FROM orders
GROUP BY status
ORDER BY count DESC;

Inspect missing fields

SELECT *
FROM orders
WHERE shipping IS NULL;

Keyboard Shortcuts

ShortcutAction
Cmd+Enter / Ctrl+EnterExecute query
Cmd+/ / Ctrl+/Toggle SQL comment

Saving SQL Work

When you save a workspace, SQL data sources and saved queries can be included:

  • Editor files become reusable SQL sources.
  • SQL-added JSON/CSV sources can become workspace files.
  • Query text can be saved as a workspace query.

Guest sessions remain local until you explicitly save or export a workspace.


Large Files

SQL is one of the best paths for large payloads because it avoids rendering every nested branch. If Graph or Explorer shows a large-file guard, use SQL when you need aggregation or joins, and use Grid when you need direct row inspection.

See Large Files for current limits and the paid large-file roadmap.