NiceGUI: Web-based user interfaces with Python. The nice way.

New features and enhancements

• Add lazy imports for the ui module to speed up startup by deferring heavy element imports until first access (#5303 by @evnchn, @falkoschindler)
• Make ValueElement and ValueChangeEventArguments generic for proper type inference of .value and event arguments (#2677, #5785 by @petergaultney, @evnchn, @falkoschindler)
• Add favicon support in native mode on Windows (#1745, #5841 by @falkoschindler, @FabianGoessling, @rodja, @DearRude, @evnchn)
• Add make_sortable() to enable drag-and-drop sorting on container elements like ui.column, ui.row, ui.card, and many more (#932, #4656, #5464, #5855 by @falkoschindler, @evnchn, @EmberLightVFX, @phifuh, @marcrichard22, @nomadfox6, @HansBambel, @sergeyyurkov1, @sukhstanford, @stepheweffie, @TM0088, @weihuan)
• Serve a Markdown representation of any NiceGUI page via Accept: text/markdown content negotiation for AI agents and CLI tools (opt-in via ui.run(markdown=True) or @ui.page(markdown=True)) (#5889 by @evnchn, @falkoschindler, @rodja)
• Raise an error when ui.run_with() is called with nicegui.app itself, preventing a self-mount loop that exhausted CPU and RAM (#5954 by @falkoschindler, @evnchn)

Bugfixes

• Add ui.keep_alive to mount children eagerly regardless of visibility, fixing data loss in unmounted ui.xterm and unresponsive ui.aggrid inside hidden tabs or dialogs (#3033, #5839, #5951 by @falkoschindler, @natankeddem, @kyloe, @amks1, @Ha44a, @evnchn)
• Fix in-page drag-and-drop in native mode being blocked by the document-level dragover handler (#5943, #5962 by @phifuh, @falkoschindler, @evnchn)
• Fix app.on_exception not catching exceptions from async event handlers (#5945, #5946 by @Rollmops, @falkoschindler, @evnchn)
• Fix PermissionError on Windows when clearing file-backed storage during shutdown (#5949, #5973 by @atollk, @rodja, @falkoschindler, @evnchn)
• Clear streaming client cookie jar between On Air range-requests to prevent unbounded memory growth (#5968 by @AAtomical, @falkoschindler, @evnchn, @stephanpalmer)
• Fix scoped CSS parsing for @keyframes and similar nested at-rules, and apply scoped selectors to the component root element via tinycss2 (#5969, #5972, #5976 by @jhjcpishva, @falkoschindler, @evnchn)
• Return JSON from the 404 handler for non-page endpoints so FastAPI routes keep their default error format (#5974 by @falkoschindler, @evnchn, @jsb-zz, @codingpaula)
• Preserve aspect ratio in ui.interactive_image when size is not set, fixing stretched sponsor logos on the website (#5978, #5980 by @lawrenceakka, @falkoschindler, @evnchn)
• Fix ReferenceError from dangling weakref proxies in ui.run_with() (#5979, #5981 by @giunio-prc, @falkoschindler, @evnchn)

Documentation

• Update Trello Cards example with drag-and-drop reordering within a column (#5934 by @entorb, @evnchn, @falkoschindler)
• Improve the xterm example with a configurable command, PTY resize, viewport sizing, and lifecycle hardening (#5959 by @evnchn, @falkoschindler)
• Add ui.aggrid demo for adding rows without losing client-side edits (#5952, #5967 by @peyman-vasegh, @falkoschindler, @evnchn)

Testing

• Fix RuntimeError when a click handler deletes the clicked element during testing (#5935, #5937, #5938 by @samuller, @falkoschindler, @evnchn)

Dependencies

• Bump pytest to v9 to address Dependabot alert 244 (#5953 by @falkoschindler, @evnchn)
• Bump softprops/action-gh-release from 2 to 3 (#5955 by @dependabot, @falkoschindler)

Special thanks to our top sponsors TestMu AI and Lechler GmbH ✨

and all our other sponsors and contributors for supporting this project!

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