DuckDB WASM: Running SQL Analytics Entirely in the Browser

The problem with server-side SQL sandboxes

Most SQL sandboxes send your query and data to a server, execute it, and return results. This has latency, privacy implications, and scalability costs.

Enter DuckDB WASM

DuckDB is an in-process OLAP database that can be compiled to WebAssembly and run entirely in the browser. You can load a 1 GB Parquet file and run analytical SQL on it — all locally, with no server round-trip.

Our implementation

The [SQL Sandbox](/sql/sandbox) uses `@duckdb/duckdb-wasm` to:

Load CSV, JSON, Parquet, or Excel files into an in-memory DuckDB instance

2. Execute any SQL against those tables

3. Return results as a data table

4. Export results in any format

Performance

On an M2 MacBook, DuckDB WASM processes ~50 million rows per second for simple aggregations. For most day-to-day analytical queries on files up to 500 MB, it's faster than many server-side databases.