Limits RegistryPUBLIC RECORDLimits RegistryResearch Console →Maximum UDF file size listed by the Microsoft filesystem functionality specification.
The question, scope, and sources behind this Registry record.
Under the recorded filesystem formats version and parameters, establish 2^64 - 1 bytes.
Current frontiers derived from accepted Claims.
The accepted equality closes this optimization result.
Assertions tied to evidence, attribution, and review.
The frontier as it changed over time.
Only accepted Claims matching the current specification contribute to the displayed bounds. Strict inequalities remain open; contradictory Claims require editorial review.
No accepted machine-checked reproductions are recorded for this Limit.
Limits Registry. LR-003707. UDF maximum file size in Windows comparison. 2026.