Free online data tools

Open spreadsheet files such as XLSX, XLS and CSV in the browser and convert them to other formats.

Run a real Postgres compiled to WebAssembly in the browser and try SQL against it.

Demo UI of sql.js, SQLite compiled to JavaScript, for running queries on in-memory databases.

Try the Papa Parse CSV parser on pasted or uploaded text and see the parsed rows and config effects.

JupyterLab running entirely in the browser with a WebAssembly Python kernel, no server needed.

DuckDB SQL shell that runs entirely in the browser via WebAssembly, reading local and remote files.

Runs the R language entirely in the browser using WebAssembly.

Datasette running in the browser through WebAssembly to explore SQLite and CSV files.

Review pane for calibrating an LLM judge: load a promptfoo CSV, mark your own labels and see where they differ from the judge.

Opens CSV, TSV or log files for searching and filtering by column.

Reads a CSV in the page and reports each column's type, gaps, spread and outliers, then drafts a data dictionary to copy.

Generates embeddings with EmbeddingGemma 2 on WebGPU directly in the browser.

Ultra-compact multilingual embedding model that runs in the browser for similarity search.

Swaps the delimiter in a CSV file, for example from commas to semicolons.

Rearranges CSV data so rows become columns.

Scans a CSV file for rows with missing or empty fields and lists them.

Inserts new columns into a CSV file at a position you choose.

Exchanges the positions of two columns in a CSV file.

Flips a CSV table so rows and columns trade places.