StellaMary 5 hours ago

Parsing .xlsx in JS with libraries like SheetJS often means:

Loading the whole 100 MB file into memory Blocking the main thread Tabs freezing, fans spinning xlsx-lite does it differently:

Streams ZIP entries (no inflate-to-Vec) Async + cooperative yielding — browser paints while parsing Batch-based parsing (rows in chunks) Memory stays flat, UI stays responsive

StellaMary 5 hours ago

For reference, my test case: a 40MB XLSX with ~200k rows.

Parsing with this WASM build: ~16ms (on Chrome, M1 Mac).

Parsing with JS (SheetJS): seconds, often >5s, with UI stutter. So the speed difference is very noticeable on big files.

Curious if anyone here has even larger datasets to try!

StellaMary 5 hours ago

Give a try and share your feed back..!! Will be sharing for react and vue ASAP.