Dev tools · September 19, 2023
Harlequin, the DuckDB IDE for Your Terminal
Hi HN - For the past four months I've been working (part-time, this is OSS after all) on Harlequin, a SQL IDE for DuckDB that runs in your terminal. I built this because I work in Data, and I found myself often reaching for the DuckDB CLI to quickly query CSV or Parquet data, but then hitting a wall when using the DuckDB CLI as my queries got more complex and my result sets got larger. Harlequin is a drop-in replacement for the DuckDB CLI that runs in any terminal (even over SSH), but adds a browsable data catalog, full-powered text editor (with multiple buffer support), and a scrollable…
What it does
In the maker’s words, at launch
Hi HN - For the past four months I've been working (part-time, this is OSS after all) on Harlequin, a SQL IDE for DuckDB that runs in your terminal. I built this because I work in Data, and I found myself often reaching for the DuckDB CLI to quickly query CSV or Parquet data, but then hitting a wall when using the DuckDB CLI as my queries got more complex and my result sets got larger. Harlequin is a drop-in replacement for the DuckDB CLI that runs in any terminal (even over SSH), but adds a browsable data catalog, full-powered text editor (with multiple buffer support), and a scrollable results viewer that can display thousands of records. Harlequin is written in Python, using the Textual framework. It's licensed under MIT. Today I released v1.0.0, and I'm excited to share Harlequin with HN for the first time. You can try it out with `pip install harlequin`, or visit https://harlequin.sh for docs and other info.
Does the same job
all alternatives →- DUDuck-UI – Browser-Based SQL IDE for DuckDBOct 2025 · demo.duckui.com · ▲213
I built Duck-UI, a web-based SQL editor that runs DuckDB entirely in your browser via WebAssembly. No backend required. The Problem: Every time I needed to query csv, parquet, or even to play with SQL, I had to either: (a) spin up a Jupyter notebook (b) use the CLI (c) upload to a hosted service. Friction at every step (TOO MUCH to load a csv or even to test some sql (study)... The Solution: DuckDB's WASM runtime lets us run SQL analysis client-side. Load CSV/JSON/Parquet files from disk or URL, write SQL, get results instantly. Data stays on your machine. What It Does: SQL editor…
- CQCSVFiddle – Query CSV files with DuckDB in the browser2022 · csvfiddle.io · ▲64
- DQDbxlite – Query 100M+ rows in a browser tab, no installDec 2025 · sql.dbxlite.com · ▲5
What started as a Claude Code experiment turned into a browser-native SQL workbench I now use daily. Runs DuckDB WASM entirely in your browser. No backend, no installation, no signup. - Query local files (CSV, Parquet, Excel) – data never leaves your machine - Handles 100M+ rows, 50GB+ files in a browser tab - Full UI: Monaco editor, schema explorer, spreadsheet-style results grid - Share SQL via URL – anyone can run your query instantly - BigQuery connector built-in (Snowflake coming) v0.2 – actively developing. Feedback welcome. GitHub (MIT):…
- DSData Studio – Open-Source Data NotebooksFeb 2026 · github.com · ▲28
Hey HN, I am Alex. I am open sourcing Data Studio, a lightweight data exploration IDE in your browser that runs locally. Try it: https://local.dataspren.com (no account needed, runs locally) More information: https://github.com/dataspren-analytics/data-studio I love working with data (Postgres, SQL, DuckDB, DBT, Iceberg, ...). I always wanted a data exploration tool that runs in my browser and just works. Without any infra or privacy concerns (DuckDB UI came quite close). Features: - Data Notebooks - SQL cells work like DBT models (they materialize to views) -…
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