Flet is an open supply Python framework that renders its UI with Flutter. You write Python, and Flet attracts Materials and Cupertino widgets on iOS, Android, Home windows, macOS, Linux and the browser. No Dart, Swift, Kotlin or JavaScript required.
Final week, the Flet crew launched Flet 1.0 and declared it prepared for constructing manufacturing apps. The discharge lands roughly 4 years after the venture began.
Is it deployable? Sure, at this time. Flet 1.0.0 is on PyPI beneath the Apache 2.0 license, requires Python 3.10 or newer for the SDK, and installs with pip set up 'flet[all]'. flet construct produces artifacts for Home windows, macOS, Linux, iOS, Android and net. The CLI accepts eight goal platforms: apk, aab, ipa, ios-simulator, home windows, macos, linux and net.
The Take a look at Matrix
Flet runs framework unit exams throughout Python 3.10 to three.14, alongside exams for the Flutter facet. Management and instance integration exams test habits and examine screenshots, catching purposeful bugs and visible regressions.
Python binary package deal exams train native libraries on Android and the iOS simulator, with the cell pipeline constructing for Python 3.12, 3.13 and three.14. flet construct integration exams compile apps throughout these Python variations for all six platforms, and flet take a look at launches a packaged app and drives it on all 5 native platforms, together with Linux ARM64.
You may write the identical sort of exams. Integration tests for your own app use pytest, run by way of flet take a look at towards the packaged construct, with screenshot comparability on Android and iOS.
Python Variations and Cell Libraries
Flet bundles Python 3.12, 3.13 or 3.14 along with your app, and net builds use the corresponding Pyodide launch. See how to choose a Python version.
The Flet package index now lists greater than 100 packages, together with NumPy, pandas, Matplotlib, Pillow, SciPy, scikit-learn, cryptography and pydantic-core, plus supporting native libraries. The mobile-forge pipeline automates wheel builds for iOS and Android. Availability nonetheless is determined by the package deal and the goal.
Efficiency and Packaging
Flet now tracks modified properties and skips pointless comparisons throughout UI reconciliation, with 0.83 benchmarks measuring as much as 6.7x enchancment in management diffing. In packaged native apps, dart-bridge lets the Python and Dart runtimes discuss inside one course of, with out sockets, with devoted channels for binary knowledge.
Packaging permits bytecode compilation by default, and redesigned Android packaging hundreds Python packages immediately from the APK with out extraction.
Declarative UI
Flet Declarative describes UI as a operate of software state, organized into reusable parts. Flet Studio and the Flet cell app are themselves declarative Flet apps. The crucial model stays supported. Evaluate each within the docs.
The compatibility policy deprecates APIs earlier than elimination, with a default deprecation interval of three minor releases.
The Flet MCP server offers AI coding assistants model particular Flet API info, plus instruments for locating examples, icons and CLI choices. Flet Studio runs within the browser with a in-built AI agent, and initiatives will be downloaded for native growth.
Interactive Explainer
The embed under walks by means of 5 mechanics: the construct pipeline throughout eight targets, declarative versus crucial state, the CI take a look at layers, runtime bundling with cell wheels, and the occasion loop lure. Colours comply with Flet’s personal model tokens.
