pypi / altair

altair

What changed in altair 5 to 6, from its official release notes, upgrade guides and advisories. Sources checked 2026-11-12.

17 breaking4 deprecations8 new APIs and options13 behavior and defaults1 tooling20 fixes and other

See which of these apply to your code, ranked, in your agent:

npx @unstale/cli init

altair 641 changes

Invalid property setter arguments now raise TypeError instead of being silently discarded.
6.3.0release notes
Support for Python 3.10 is dropped.
6.3.0release notes
Python 3.9 is dropped; the release also adds pandas 3 compatibility.
6.1.0release notes
The default stack order of marks like bars and areas is now aligned with the color domain.
6.1.0release notes
Parameter and view names are now hashed.
6.0.0release notes
Altair now compiles against Vega-Lite 6, specifically 6.1.0, so projects must use Vega-Lite 6 or later.
6.0.0release notes
The minimum required vegafusion version is now 2.
6.0.0release notes

Signals and params can now be passed to alt.datum[...] directly, instead of interpolating a parameter name into a string.
6.3.0release notes
Expression objects now work as arguments to alt.value().
6.3.0release notes
Adds the ensure_ascii option to to_json(), with a default of False.
6.1.0release notes
A new datasets module provides lazy access to datasets from vega-datasets.
6.0.0release notes

The olli integration is updated to v3.
6.2.0release notes
Layering simple faceted charts that define the same facet variables is supported, instead of requiring layering before faceting.
6.1.0release notes
Interactive charts automatically change the cursor to pointer to indicate they can be interacted with.
6.1.0release notes
Tooltips now support newlines.
6.1.0release notes
The height and width types changed from int to float.
6.0.0release notes
Altair expressions now allow NumPy scalar values.
6.0.0release notes
Altair is now thread-safe, and specifications should remain stable after re-running.
6.0.0release notes
Altair now emits a warning for deduplications.
6.0.0release notes
The editor can now be opened without validating the specification.
6.0.0release notes
The .changed property is now optional in JupyterChart.
6.0.0release notes
MaxRowsError messages now show user_rows.
6.0.0release notes
ValidationError messages now show Python types, providing more information when validation fails.
6.0.0release notes

Missing anywidget is now reported for JupyterChart.
6.3.0release notes
Avoids view name collisions in layered concatenations.
6.2.2release notes
Includes layered concat views in selection parameters.
6.2.2release notes
Dataset cache files are now written atomically.
6.2.1release notes
Params are propagated to the outer level after add_params in concat charts.
6.2.0release notes
Fixes type issues with Chart mark methods.
6.1.0release notes
Fixes type issues with Chart save methods.
6.1.0release notes
Fixes typing issues for mypy 1.18 and above.
6.1.0release notes
Preserves polars datetime timezones during serialization.
6.1.0release notes
Identical specs that use different data now receive unique hashes.
6.1.0release notes
Fixes non-unique view names per concat cell and corrects param.views.
6.1.0release notes
Altair now accepts ZoneInfo(key='UTC').
6.1.0release notes
The typing for ChartType.data was corrected to resolve an LSP violation.
6.0.0release notes
The &, |, and ~ operators now preserve the empty property.
6.0.0release notes
The overload no longer incorrectly indicates that True is the default for strict.
6.0.0release notes
Altair now provides support for Python 3.14.
6.0.0release notes
Vega export was repaired.
6.0.0release notes

The altair.sphinxext module has been removed; the altair-plot Sphinx directive is now part of the sphinxext-altair package.
5.0.0release notes
Escape colons in column names to avoid ambiguity with encoding types, for example "column\:name" instead of "column:name".
5.0.0release notes
The deprecated datasets.py module has been removed.
5.0.0release notes
Specify a selection parameter's empty keyword argument as True or False instead of all or none, respectively.
5.0.0release notes
Ordered pandas categorical data are automatically encoded as sorted ordinal data.
5.0.0release notes
Parameters are introduced, including variable parameters and selection parameters, enabling interactive charts and replacing much of the old selection terminology.
5.0.0release notes
In many cases, replace the selection keyword argument with param, such as when specifying a filter transform.
5.0.0release notes
The Vega-Lite 3 and 4 wrappers have been removed.
5.0.0release notes
Rendering in Vega mode is deprecated, although saving a Chart as Vega format remains allowed.
5.0.0release notes
The default chart width changed from 400 to 300.
5.0.0release notes

add_selection is deprecated; use add_params instead.
5.0.0release notes
The init keyword argument for a parameter is deprecated; use value instead.
5.0.0release notes
Use selection_point in place of the deprecated selection_single and selection_multi APIs.
5.0.0release notes
For point selections, use type=point instead of the deprecated type=single or type=multi.
5.0.0release notes

Experimental DataFrame Interchange Protocol support is available through the __dataframe__ attribute and requires pyarrow>=11.0.0.
5.0.0release notes
Channel options can be set with method-based syntax, such as alt.X(...).bin(...), alongside the existing attribute-based syntax.
5.0.0release notes
Offset channels support grouped bar charts and jitter.
5.0.0release notes
Set width="container" for responsive charts when saving to HTML or using the default html renderer.
5.0.0release notes

HTML chart saving supports inline output without requiring altair_saver to be installed.
5.0.0release notes

Displaying a chart no longer changes the shorthand syntax in the stored spec.
5.0.0release notes
disable_debug_mode is fixed.
5.0.0release notes
A webdriver issue affecting Firefox's geckodriver is fixed.
5.0.0release notes