JupyterLab 4.5: contentVisibility and Auto Theme

JupyterLab 4.5 speeds up rendering with contentVisibility and adds an auto theme.

Overview

JupyterLab 4.5, released on November 18, 2025, adds contentVisibility for cells, streamed uploads and an auto theme.

Main Features

contentVisibility and streaming

Off-screen cells use contentVisibility to speed up rendering of large notebooks. File uploads are now streamed.

python

# Large notebooks automatically benefit from
# contentVisibility for off-screen cells

# Auto theme follows system preferences
# Settings > Theme > Theme auto-detection: enabled

Auto theme

The new auto theme mode detects system preferences (light/dark) and adapts the interface accordingly.

Sources

JupyterLab Changelog