Archive size estimate
Estimate how large a ZIP archive's contents would be when extracted, without extracting anything.
Working…
Questions people ask
- How does the tool know the sizes without extracting?
- It does not read them directly; the archive declares them. The report is built entirely from the ZIP's central directory (the header records listing every member's stored and declared sizes), and every figure is labelled a declared estimate rather than an independently verified extraction result. No payload byte is ever opened.
- What makes a member "suspicious"?
- An expansion ratio of 1000x or more (the member declares at least a thousand times its stored size, and at least 512 bytes of stored data). Suspicious members are listed by name with both figures, the classic shape of a zip bomb, and the report never opens them.
- Could a hostile archive lie about its size?
- It could, and this tool cannot catch every lie, because that would mean reading the contents (which would defeat the purpose). The figures carry an explicit label: they are the archive's own declarations. The platform's extraction tools enforce their own caps regardless of what an archive claims.
- What about encrypted or unsupported members?
- They are counted and classed (names, sizes, methods) but never opened: the same read-only approach the other archive tools in this catalogue take.