VIR Wasm Size Explorer

Area means raw retained bytes. A block twice as large owns twice as many bytes in the linked binary.

Ownership comes from wasm-ld --Map. Drill from a subsystem into an object/module and then a retained symbol.

Gzip is intentionally not apportioned. Compression depends on neighboring bytes, so per-symbol gzip estimates are not additive.

Runtime context uses a different unit. It measures installed native archive-member bytes and follows Lean's source hierarchy; archive provenance remains on every leaf.

Files expand into native functions and exact ELF byte classes. Positive-sized function symbols are separated from other executable code, runtime data, exception tables, relocations, symbol/name tables, debug information, and ELF metadata/alignment. Zero-fill memory is reported in details but has no archive-byte area.

Retained-code color is computed. Green intensity is the share of archive bytes belonging to exact native-function matches retained in VIR; directory, archive, and layer colors are byte-weighted child averages.

Zoom depth is local and sticky. The slider controls how many descendant levels are drawn below the current breadcrumb and keeps its setting while you drill in.

Frontier pressure is measured, not predicted. Color is blocker-root density per MiB; parent density is the byte-weighted average of its children. The focused log scale keeps sparse parent averages pale so concentrated leaves stand out. A repaired boundary may reveal another blocker.

The combined view exposes overlap. Green is retained code, orange is frontier pressure, purple has both signals, and gray has neither. A retained native function can still be unavailable through the extern catalog.