Is DuckDB Browser Safe?

Yes — the DuckDB Browser is one of the safest tools on DevToolSets because it runs entirely in your browser. Here's why:

Your Data Never Leaves Your Machine

DuckDB runs via WebAssembly inside your browser tab. When you load a file, it's read into your browser's memory — it's never uploaded to any server. All queries execute locally on your device.

No Credentials Required

Unlike the Postgres or MySQL tools, DuckDB Browser doesn't need any connection credentials. There's no server to connect to, no passwords to manage, and no network requests for queries.

Data Is Ephemeral

Everything is stored in memory. When you close or refresh the tab, all data is gone. Only your query history persists (stored in IndexedDB).

Works Offline

Once the page is loaded, the DuckDB WASM engine runs independently. You can disconnect from the internet and continue querying your data.

Best Practices

• Export your results before closing the tab — data doesn't persist
• For very large files, make sure your device has enough available RAM
• Use Parquet format for the best performance and lowest memory usage