mjml

library0.12.0pypypi✓ verified 85d ago

mjml-python is a Python implementation and wrapper around the high-performance Rust MJML engine MRML. It allows compiling MJML markup into responsive HTML without requiring a Node.js runtime, external API calls, or subprocesses. The current version is 0.12.0. Releases are published as needed, often reflecting updates to the underlying MJML standard or significant bug fixes.

serialization communication

pip install mjml

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · MJML

mjml

serializationpythonv0.12.0

Install

2.1s avg

Import

554ms

Disk

20MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.12.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.920 runs

installs and imports cleanly · install 0.0s · import 0.572s · 21.2MB

glibc

py 3.10–3.920 runs

installs and imports cleanly · install 2.1s · import 0.536s · 22MB

20MB installed

● package 20MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

mjml2html

✓ from mjml import mjml2html

This quickstart demonstrates the core functionality: importing `mjml2html` and passing an MJML string to it. The function returns a `Result` object containing the compiled HTML and any potential errors.

from mjml import mjml2html mjml_template = ''' <mjml> <mj-body> <mj-section> <mj-column> <mj-text font-size="20px" color="#F45E43" font-family="Open Sans">Hello, MJML!</mj-text> <mj-button href="https://mjml.io/" background-color="#F45E43">Learn More</mj-button> </mj-column> </mj-section> </mj-body> </mjml> ''' result = mjml2html(mjml_template) if result.errors: print("MJML compilation errors:", result.errors) else: print(result.html)

Debug

Known issues

breakingVersion 0.12.0 officially dropped support for Python 3.6, 3.7, and 3.8. Users on these Python versions must either upgrade their Python environment or pin to an older `mjml` release.

fix

Upgrade to Python 3.9 or newer (e.g., `python -m pip install --upgrade python` if using pyenv, or use a newer system Python). Alternatively, pin `mjml<0.12.0` for older Python versions.

affects: 0.12.0+

breakingThe `css-inline` dependency underwent incompatible API changes across `mjml` versions. Notably, `0.9.1` pinned `css_inline < 0.10`, while `0.10.0` required `css-inline >= 0.11` (which broke Python 3.6), and `0.11.1` accepted `css_inline >= 0.14`. Mixing `mjml` versions or `css-inline` manually can lead to runtime errors.

fix

Always install `mjml` directly via `pip install mjml` without pinning `css-inline` to ensure compatible versions are pulled. If issues arise, check your `pip freeze` output for `css-inline` version conflicts.

affects: 0.9.1, 0.10.0, 0.11.x

breakingA security vulnerability (CVE-2024-26151) was fixed in `v0.11.0` where potentially untrusted input could be rendered directly as HTML, leading to script injection. Users of `0.10.0` are strongly encouraged to upgrade.

fix

Upgrade to `mjml==0.11.0` or newer immediately via `pip install --upgrade mjml`.

affects: 0.10.0

gotchaAs of v0.12.0, comments within your MJML code (``) will now be preserved and present in the generated HTML output by default. In previous versions, these comments might have been stripped.

fix

If you need to remove comments, use the `disable_comments=True` option when calling `mjml2html(mjml_string, disable_comments=True)`.

affects: 0.12.0+

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'mjml'

The `mjml` package has not been installed in the current Python environment.

fix

Install the package using pip: `pip install mjml`.

TypeError: 'module' object is not callable

Attempting to call the `mjml` module directly instead of its `mjml2html` function.

fix

Ensure you are calling the `mjml2html` function: `from mjml import mjml2html; html = mjml2html(...)`.

RuntimeError: Unable to load shared library 'libmjml_python_core.so' or 'mjml_python_core.dll'

This error typically occurs when the underlying Rust binary (MRML) cannot be loaded, usually due to an incompatible system architecture, missing C++ runtime libraries (on Windows), or issues during installation.

fix

Ensure you are on a supported operating system and architecture. For Windows, ensure the Visual C++ Redistributable is installed. Try reinstalling with verbose output to check for build errors: `pip install mjml --verbose`.

Upgrade

Version history

0.12.0latest on PyPI · released Dec 27, 2025

Audit

Dependencies

css-inlinerequiredUsed for inlining CSS directly into the HTML output, which is crucial for email client compatibility.

Agent activity

21 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/FelixSchwarz/mjml-python ↗

packagehttps://pypi.org/project/mjml/ ↗

homepagehttps://mjml.io ↗