skillfed

flask-babel

Adds i18n/l10n support for Flask applications.

flask-babel v4.0.0 15.6M downloads/30d#1,179 on PyPI452
Permissive license BSD-3-Clause DORMANT released

What it is and what it does

Flask-Babel integrates the Babel and pytz libraries into Flask applications to provide internationalization and localization capabilities. It handles message translation, date and time formatting across different locales, and timezone conversions, allowing a single Flask application to serve content in multiple languages and regional formats.

The package works by decorating your Flask app with Babel support, then using Babel's translation and formatting functions within your templates and Python code. It relies on Flask, Babel, pytz, and Jinja2 as runtime dependencies. The project is in production-stable status and supports Python 3.8 through 3.11, though maintenance has been dormant since late 2023.

Use it for:

  • Build a Flask web application that serves the same content in multiple languages based on user preference or browser locale.
  • Format dates, times, and numbers according to regional conventions (e.g., DD/MM/YYYY vs MM/DD/YYYY) without manual logic.
  • Display timezone-aware timestamps correctly for users in different geographic regions.
  • Translate user-facing strings in Jinja2 templates and Python view functions using gettext-style message catalogs.
  • Support currency and number formatting that respects locale-specific conventions (decimal separators, thousand separators).

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Adds internationalization (i18n) and localization (l10n) support to Flask applications using Babel and pytz for date, time, and message translation.

Yes, if you need i18n/l10n in a Flask application. The package is production-stable, has low install friction, and no known vulnerabilities. The dormant maintenance is a minor concern—verify compatibility with your Flask and Babel versions before adopting, but the established user base and simple dependency chain make it a reliable choice for multi-language Flask projects.

Install

flask-babel on PyPI

pip

pip install flask-babel

uv

uv add flask-babel

poetry

poetry add flask-babel

Installing flask-babel

Before you install

Low install friction with a pure-Python wheel distribution. Dormant maintenance status (last commit 2024-08-07, no release since 2023-10-02) but stable and widely used in production; 452 repository stars indicate established adoption.

License in practice

BSD-3-Clause is permissive; you can use, modify, and distribute this package freely in commercial and private projects with minimal restrictions.

Quickstart

pip install flask-babel

from flask import Flask
from flask_babel import Babel

app = Flask(__name__)
Babel(app)

Verify before relying

  • Whether dormant maintenance (last release over 10 months old) affects compatibility with recent Flask or Babel versions.
  • Whether the package handles all modern locale and timezone edge cases or if newer alternatives are more actively maintained.

Package facts

License BSD-3-Clause (permissive)
Python support supports the current Python release (>=3.8,<4.0)
Install friction low — pure-Python wheel
Runtime dependencies 4 — pytz, Flask, Babel, Jinja2
Maintenance dormant — 1,047 days since the last release
Last repo commit
First released
Downloads 15,609,483/month — #1,179 on PyPI (30-day window, as of 2026-08-14)
Known vulnerabilities none known (OSV.dev, checked 2026-08-14)

Evidence: flask_babel-4.0.0-py3-none-any.whl

Development Status :: 5 - Production/StableEnvironment :: Web EnvironmentIntended Audience :: DevelopersLicense :: OSI Approved :: BSD LicenseOperating System :: OS IndependentProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9Programming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: PyPyTopic :: Internet :: WWW/HTTP :: Dynamic ContentTopic :: Software Development :: Libraries :: Python Modules

Tags

flask internationalization i18nflask localization l10nflask multi-language supportflask babel translationflask timezone handlingflask message translationflask language switching
i18n-l10nflask-extensiontranslation

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