Angular Spreadsheet Freezing on Large Excel Imports? Here’s the Fix

Large Excel imports in Angular apps freeze the browser because synchronous XLSX parsing blocks the main thread. Three techniques using Syncfusion Angular Spreadsheet Editor can fix this: (1) Use WorkbookParseOptions with IgnoreStyle and IgnoreFormat to skip formatting overhead and load only raw cell data; (2) Set MaximumDataLimit and MaximumFileSize thresholds server-side to block oversized uploads before they crash the app; (3) Use openFromJson with selective deserialization to avoid repeated XLSX parsing. Performance benchmarks show 500,000 cells can be imported in ~4 seconds with near-linear scaling.