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Releases: vega/altair

Version 6.1.0

21 Apr 14:51

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What's Changed

There are many exciting improvements in this release! Read on for details and a big thanks to everyone who contributed 🎉

Enhancements

  • feat: Update to Vega-Lite 6.4.1 by @joelostblom in #4005. See the Vega-Lite Release Notes for details; a few highlights:
    • Newlines are now supported in tooltips.
    • The default stack order of marks like bars and areas is now aligned with the color domain.
    • Interactive charts automatically change the cursor to pointer to indicate they can be interacted with.
  • feat: auto hoist facet encodings in layer by @thomascamminady in #3965
    • This allows layering of simple faceted charts that define the same facet variables, instead of requiring that layering happens before faceting.
  • feat: Accept ZoneInfo(key='UTC') by @JackKelly in #3944
  • feat: add pandas 3 compatibility and fix CI (drop Python 3.9, pin polars <1.38) by @mattijn in #3950
  • feat: add ensure_ascii option to to_json() with default False by @RamiNoodle733 in #3952

Bug Fixes

Documentation

Other Changes

New Contributors

Full Changelog: v6.0.0...v6.1.0

Weekly Build 6.1.0.dev20260420

20 Apr 04:07
e093674

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Pre-release

Weekly Pre-Release Build of Altair

This is a pre-release version for testing purposes.

Build Information

Version: 6.1.0.dev20260420
Tag: weekly-20260420-e093674
Previous Weekly Tag: weekly-20260413-127f79f7

Installation

From PyPI (recommended)

Install the latest weekly build directly from PyPI:

pip install altair==6.1.0.dev20260420
# or
uv pip install altair==6.1.0.dev20260420

Note: Weekly builds publish timestamped development versions (for example 6.1.0.dev20260420) to PyPI. When you pin that exact version, pip installs the dev build automatically, without the need for a --pre flag.

From GitHub Repository (direct install)

Install directly from the tagged commit without downloading the wheel:

Command line (pip or uv):

pip install git+https://github.com/vega/altair.git@weekly-20260420-e093674
# or
uv pip install git+https://github.com/vega/altair.git@weekly-20260420-e093674

Note: Installing directly from the weekly-... tag will surface the base development version (without the timestamp suffix) because the version file edits are not committed.

Add to pyproject.toml (pip/uv):

[project]
dependencies = [
    "altair @ git+https://github.com/vega/altair.git@weekly-20260420-e093674",
]

Add to pixi.toml (pixi):

[pypi-dependencies]
altair = { git = "https://github.com/vega/altair.git", rev = "weekly-20260420-e093674" }

From GitHub Release (manual download)

Download the wheel or sdist from the release assets and install, for example:

pip install ./altair-6.1.0.dev20260420-py3-none-any.whl

Testing & Feedback

Please note: This is a testing version. If you encounter any issues or unexpected behavior, we would greatly appreciate if you open an issue to report it. Your feedback helps improve Altair!

Weekly Build 6.1.0.dev20260413

13 Apr 04:07
127f79f

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Pre-release

Weekly Pre-Release Build of Altair

This is a pre-release version for testing purposes.

Build Information

Version: 6.1.0.dev20260413
Tag: weekly-20260413-127f79f7
Previous Weekly Tag: weekly-20260406-3260a3fe

Installation

From PyPI (recommended)

Install the latest weekly build directly from PyPI:

pip install altair==6.1.0.dev20260413
# or
uv pip install altair==6.1.0.dev20260413

Note: Weekly builds publish timestamped development versions (for example 6.1.0.dev20260413) to PyPI. When you pin that exact version, pip installs the dev build automatically, without the need for a --pre flag.

From GitHub Repository (direct install)

Install directly from the tagged commit without downloading the wheel:

Command line (pip or uv):

pip install git+https://github.com/vega/altair.git@weekly-20260413-127f79f7
# or
uv pip install git+https://github.com/vega/altair.git@weekly-20260413-127f79f7

Note: Installing directly from the weekly-... tag will surface the base development version (without the timestamp suffix) because the version file edits are not committed.

Add to pyproject.toml (pip/uv):

[project]
dependencies = [
    "altair @ git+https://github.com/vega/altair.git@weekly-20260413-127f79f7",
]

Add to pixi.toml (pixi):

[pypi-dependencies]
altair = { git = "https://github.com/vega/altair.git", rev = "weekly-20260413-127f79f7" }

From GitHub Release (manual download)

Download the wheel file from the assets below and install:

pip install altair-6.1.0.dev20260413-py3-none-any.whl

Testing & Feedback

Please note: This is a testing version. If you encounter any issues or unexpected behavior, we would greatly appreciate if you open an issue to report it. Your feedback helps improve Altair!

Weekly Build 6.1.0.dev20260406

06 Apr 04:02
3260a3f

Choose a tag to compare

Pre-release

Weekly Pre-Release Build of Altair

This is a pre-release version for testing purposes.

Build Information

Version: 6.1.0.dev20260406
Tag: weekly-20260406-3260a3fe
Previous Weekly Tag: weekly-20260330-5fa5ea4e

Installation

From PyPI (recommended)

Install the latest weekly build directly from PyPI:

pip install altair==6.1.0.dev20260406
# or
uv pip install altair==6.1.0.dev20260406

Note: Weekly builds publish timestamped development versions (for example 6.1.0.dev20260406) to PyPI. When you pin that exact version, pip installs the dev build automatically, without the need for a --pre flag.

From GitHub Repository (direct install)

Install directly from the tagged commit without downloading the wheel:

Command line (pip or uv):

pip install git+https://github.com/vega/altair.git@weekly-20260406-3260a3fe
# or
uv pip install git+https://github.com/vega/altair.git@weekly-20260406-3260a3fe

Note: Installing directly from the weekly-... tag will surface the base development version (without the timestamp suffix) because the version file edits are not committed.

Add to pyproject.toml (pip/uv):

[project]
dependencies = [
    "altair @ git+https://github.com/vega/altair.git@weekly-20260406-3260a3fe",
]

Add to pixi.toml (pixi):

[pypi-dependencies]
altair = { git = "https://github.com/vega/altair.git", rev = "weekly-20260406-3260a3fe" }

From GitHub Release (manual download)

Download the wheel file from the assets below and install:

pip install altair-6.1.0.dev20260406-py3-none-any.whl

Testing & Feedback

Please note: This is a testing version. If you encounter any issues or unexpected behavior, we would greatly appreciate if you open an issue to report it. Your feedback helps improve Altair!

Weekly Build 6.1.0.dev20260330

30 Mar 04:02
5fa5ea4

Choose a tag to compare

Pre-release

Weekly Pre-Release Build of Altair

This is a pre-release version for testing purposes.

Build Information

Version: 6.1.0.dev20260330
Tag: weekly-20260330-5fa5ea4e
Previous Weekly Tag: weekly-20260323-98de0277

Installation

From PyPI (recommended)

Install the latest weekly build directly from PyPI:

pip install altair==6.1.0.dev20260330
# or
uv pip install altair==6.1.0.dev20260330

Note: Weekly builds publish timestamped development versions (for example 6.1.0.dev20260330) to PyPI. When you pin that exact version, pip installs the dev build automatically, without the need for a --pre flag.

From GitHub Repository (direct install)

Install directly from the tagged commit without downloading the wheel:

Command line (pip or uv):

pip install git+https://github.com/vega/altair.git@weekly-20260330-5fa5ea4e
# or
uv pip install git+https://github.com/vega/altair.git@weekly-20260330-5fa5ea4e

Note: Installing directly from the weekly-... tag will surface the base development version (without the timestamp suffix) because the version file edits are not committed.

Add to pyproject.toml (pip/uv):

[project]
dependencies = [
    "altair @ git+https://github.com/vega/altair.git@weekly-20260330-5fa5ea4e",
]

Add to pixi.toml (pixi):

[pypi-dependencies]
altair = { git = "https://github.com/vega/altair.git", rev = "weekly-20260330-5fa5ea4e" }

From GitHub Release (manual download)

Download the wheel file from the assets below and install:

pip install altair-6.1.0.dev20260330-py3-none-any.whl

Testing & Feedback

Please note: This is a testing version. If you encounter any issues or unexpected behavior, we would greatly appreciate if you open an issue to report it. Your feedback helps improve Altair!

Weekly Build 6.1.0.dev20260323

23 Mar 03:55
98de027

Choose a tag to compare

Pre-release

Weekly Pre-Release Build of Altair

This is a pre-release version for testing purposes.

Build Information

Version: 6.1.0.dev20260323
Tag: weekly-20260323-98de0277
Previous Weekly Tag: weekly-20260316-49e745b8

Installation

From PyPI (recommended)

Install the latest weekly build directly from PyPI:

pip install altair==6.1.0.dev20260323
# or
uv pip install altair==6.1.0.dev20260323

Note: Weekly builds publish timestamped development versions (for example 6.1.0.dev20260323) to PyPI. When you pin that exact version, pip installs the dev build automatically, without the need for a --pre flag.

From GitHub Repository (direct install)

Install directly from the tagged commit without downloading the wheel:

Command line (pip or uv):

pip install git+https://github.com/vega/altair.git@weekly-20260323-98de0277
# or
uv pip install git+https://github.com/vega/altair.git@weekly-20260323-98de0277

Note: Installing directly from the weekly-... tag will surface the base development version (without the timestamp suffix) because the version file edits are not committed.

Add to pyproject.toml (pip/uv):

[project]
dependencies = [
    "altair @ git+https://github.com/vega/altair.git@weekly-20260323-98de0277",
]

Add to pixi.toml (pixi):

[pypi-dependencies]
altair = { git = "https://github.com/vega/altair.git", rev = "weekly-20260323-98de0277" }

From GitHub Release (manual download)

Download the wheel file from the assets below and install:

pip install altair-6.1.0.dev20260323-py3-none-any.whl

Testing & Feedback

Please note: This is a testing version. If you encounter any issues or unexpected behavior, we would greatly appreciate if you open an issue to report it. Your feedback helps improve Altair!

Weekly Build 6.1.0.dev20260316

16 Mar 04:01
49e745b

Choose a tag to compare

Pre-release

Weekly Pre-Release Build of Altair

This is a pre-release version for testing purposes.

Build Information

Version: 6.1.0.dev20260316
Tag: weekly-20260316-49e745b8
Previous Weekly Tag: weekly-20260309-356c78bb

Installation

From PyPI (recommended)

Install the latest weekly build directly from PyPI:

pip install altair==6.1.0.dev20260316
# or
uv pip install altair==6.1.0.dev20260316

Note: Weekly builds publish timestamped development versions (for example 6.1.0.dev20260316) to PyPI. When you pin that exact version, pip installs the dev build automatically, without the need for a --pre flag.

From GitHub Repository (direct install)

Install directly from the tagged commit without downloading the wheel:

Command line (pip or uv):

pip install git+https://github.com/vega/altair.git@weekly-20260316-49e745b8
# or
uv pip install git+https://github.com/vega/altair.git@weekly-20260316-49e745b8

Note: Installing directly from the weekly-... tag will surface the base development version (without the timestamp suffix) because the version file edits are not committed.

Add to pyproject.toml (pip/uv):

[project]
dependencies = [
    "altair @ git+https://github.com/vega/altair.git@weekly-20260316-49e745b8",
]

Add to pixi.toml (pixi):

[pypi-dependencies]
altair = { git = "https://github.com/vega/altair.git", rev = "weekly-20260316-49e745b8" }

From GitHub Release (manual download)

Download the wheel file from the assets below and install:

pip install altair-6.1.0.dev20260316-py3-none-any.whl

Testing & Feedback

Please note: This is a testing version. If you encounter any issues or unexpected behavior, we would greatly appreciate if you open an issue to report it. Your feedback helps improve Altair!

Weekly Build 6.1.0.dev20260309

09 Mar 03:49
356c78b

Choose a tag to compare

Pre-release

Weekly Pre-Release Build of Altair

This is a pre-release version for testing purposes.

Build Information

Version: 6.1.0.dev20260309
Tag: weekly-20260309-356c78bb
Previous Weekly Tag: weekly-20260223-903e68e1

Installation

From PyPI (recommended)

Install the latest weekly build directly from PyPI:

pip install altair==6.1.0.dev20260309
# or
uv pip install altair==6.1.0.dev20260309

Note: Weekly builds publish timestamped development versions (for example 6.1.0.dev20260309) to PyPI. When you pin that exact version, pip installs the dev build automatically, without the need for a --pre flag.

From GitHub Repository (direct install)

Install directly from the tagged commit without downloading the wheel:

Command line (pip or uv):

pip install git+https://github.com/vega/altair.git@weekly-20260309-356c78bb
# or
uv pip install git+https://github.com/vega/altair.git@weekly-20260309-356c78bb

Note: Installing directly from the weekly-... tag will surface the base development version (without the timestamp suffix) because the version file edits are not committed.

Add to pyproject.toml (pip/uv):

[project]
dependencies = [
    "altair @ git+https://github.com/vega/altair.git@weekly-20260309-356c78bb",
]

Add to pixi.toml (pixi):

[pypi-dependencies]
altair = { git = "https://github.com/vega/altair.git", rev = "weekly-20260309-356c78bb" }

From GitHub Release (manual download)

Download the wheel file from the assets below and install:

pip install altair-6.1.0.dev20260309-py3-none-any.whl

Testing & Feedback

Please note: This is a testing version. If you encounter any issues or unexpected behavior, we would greatly appreciate if you open an issue to report it. Your feedback helps improve Altair!

Weekly Build 6.1.0.dev20260223

23 Feb 03:52
903e68e

Choose a tag to compare

Pre-release

Weekly Pre-Release Build of Altair

This is a pre-release version for testing purposes.

Build Information

Version: 6.1.0.dev20260223
Tag: weekly-20260223-903e68e1
Previous Weekly Tag: weekly-20260216-e85e1e3b

Installation

From PyPI (recommended)

Install the latest weekly build directly from PyPI:

pip install altair==6.1.0.dev20260223
# or
uv pip install altair==6.1.0.dev20260223

Note: Weekly builds publish timestamped development versions (for example 6.1.0.dev20260223) to PyPI. When you pin that exact version, pip installs the dev build automatically, without the need for a --pre flag.

From GitHub Repository (direct install)

Install directly from the tagged commit without downloading the wheel:

Command line (pip or uv):

pip install git+https://github.com/vega/altair.git@weekly-20260223-903e68e1
# or
uv pip install git+https://github.com/vega/altair.git@weekly-20260223-903e68e1

Note: Installing directly from the weekly-... tag will surface the base development version (without the timestamp suffix) because the version file edits are not committed.

Add to pyproject.toml (pip/uv):

[project]
dependencies = [
    "altair @ git+https://github.com/vega/altair.git@weekly-20260223-903e68e1",
]

Add to pixi.toml (pixi):

[pypi-dependencies]
altair = { git = "https://github.com/vega/altair.git", rev = "weekly-20260223-903e68e1" }

From GitHub Release (manual download)

Download the wheel file from the assets below and install:

pip install altair-6.1.0.dev20260223-py3-none-any.whl

Testing & Feedback

Please note: This is a testing version. If you encounter any issues or unexpected behavior, we would greatly appreciate if you open an issue to report it. Your feedback helps improve Altair!

v6.0.0

12 Nov 11:01
8693285

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Release v6.0.0

The Vega-Altair team is pleased to announce the release of version 6.0.0. Firstly, we are grateful for the many returning contributors (@franzhaas, @dangotbanned, @dsmedia, @joelostblom, @tempdata73, @mattijn, @jonmmease, @eitanlees, @kurtmckee, @MarcoGorelli), and a special shoutout to all the new contributors (@JasonnnW3000, @edmundmiller, @jannisko, @stanmart, @star1327p, @baldwint, @daizutabi, @azjps, @joaopalmeiro, @bobot). You are all awesome!

In short what is included with the version 6 release of Altair.

  • we now compile against Vega-Lite version 6 (to be specific, version 6.1.0) and provide support for Python 3.14.
  • we have a new datasets module, altair.datasets, lazily access to datasets from https://github.com/vega/vega-datasets.
  • we are now thread-safe, altair specifications should be stable after re-running.
  • we improved docs and included new examples, eg. this faceted choropleth of habitat species across geographical counties https://altair-viz.github.io/gallery/maps_faceted_species.html.
  • we improved the typing experiences.
  • we migrated to uv as part of the infrastructure modernization and now have automated weekly builds.

We test all changes thoroughly, but nevertheless, if you encounter any issue or like to start a discussion. Please feel free!

Full details are available in the complete changelog below.

Breaking

Enhancements

Bug Fixes

Documentation

Other Changes

Read more