Windows 11 monthly updates now exceed 4GB to 5GB, driven partly by AI components bundled into cumulative packages

Monthly cumulative updates downloaded from Microsoft Update Catalog now regularly cross 4GB, and in recent cases touch 5GB; the May 2025 cumulative update jumped to over 4GB in the catalog, nearly tripling from April 2025's 1,287 MB.

The May 2025 size increase was attributable to dozens of MSIX files related to semantic search and on-device AI (PSTokenizer, Text Recognition Session, PSOnyxRuntime, Query Processor Session, Image Search Session), accounting for approximately 3GB of the delta; however, applicability logic means these components do not download to all machines—a fresh Windows 11 25H2 install on a VM downloaded only around 1.7GB from a 4GB+ catalog package because Semantic Search components did not apply to that machine.

Microsoft uses Checkpoint Cumulative Updates (introduced in Windows 11 24H2) to reset the baseline periodically so monthly updates only include changes since the last checkpoint; after a checkpoint was established in September 2024, updates remained relatively small through April 2025, but no new checkpoint has been set for a year, causing the promised size savings to erode.