What is Preswald used for?

Preswald packages Python data apps with Pyodide and DuckDB into static files that run fully in the browser, offline, and can be shared like a document. It is a good fit for sharing dashboards as a single file and local-only analysis of sensitive data.

Is Preswald open source?

Yes. Preswald is open source under the Apache-2.0 licence. Its source code is on GitHub at StructuredLabs/preswald and is written mainly in Python.

Yes. Preswald is open source, so the software itself is free to use.

What is Preswald an alternative to?

Preswald is an open-source alternative to Hex. Other open-source alternatives to Hex include Redash, Shaper and Evidence.

Is Preswald actively maintained?

The most recent commit to Preswald was on 11 June 2026, and the latest release is v0.1.59, published on 5 June 2025. The project has 4.3k stars on GitHub.

Preswald: open-source alternative to Hex

About Preswald

Preswald is a static-site generator and WASM packager for interactive data apps written in Python. It bundles compute, data access and a user interface into self-contained apps that run locally in the browser, using Pyodide and DuckDB along with libraries such as Pandas, Plotly and Matplotlib.

Apps are written in Python rather than notebooks or JavaScript frameworks, and one command builds a packaged HTML app into a dist folder that can be shared. Built-in components such as tables, charts and forms and a reactive engine based on a dependency graph re-run only what is needed. The project argues it is useful when you want to ship a tool to someone who should not need to install anything, when working with sensitive data that should stay under local control, or when you want AI systems to be able to inspect and modify structured tools.

There is no server, so apps work offline even with large data. Preswald is licensed under Apache-2.0 and is a lightweight alternative to heavier web app platforms for dashboards, reports, prototypes and notebooks.

Key features

Python apps packaged as static HTML
Runs entirely in the browser with Pyodide
DuckDB for in-browser data queries
Reactive engine with dependency graph
Built-in tables, charts and forms
Offline use with no server

Good fit for

→Sharing dashboards as a single file
→Local-only analysis of sensitive data

Built with: Python
Tags: data-apps; wasm; pyodide; duckdb; python; dashboards; analytics; offline

Preswald: questions and answers

What is Preswald used for?: Preswald packages Python data apps with Pyodide and DuckDB into static files that run fully in the browser, offline, and can be shared like a document. It is a good fit for sharing dashboards as a single file and local-only analysis of sensitive data.
Is Preswald open source?: Yes. Preswald is open source under the Apache-2.0 licence. Its source code is on GitHub at StructuredLabs/preswald and is written mainly in Python.
Is Preswald free?: Yes. Preswald is open source, so the software itself is free to use.
What is Preswald an alternative to?: Preswald is an open-source alternative to Hex. Other open-source alternatives to Hex include Redash, Shaper and Evidence.
Is Preswald actively maintained?: The most recent commit to Preswald was on 11 June 2026, and the latest release is v0.1.59, published on 5 June 2025. The project has 4.3k stars on GitHub.