Zero-Egress In-Browser Document Processing Systems Using Web Workers

Abstract Cloud-based document processing services expose enterprise workflows to severe network latency overhead, recurring API financial costs, and catastrophic data breach liability through remote payload transit. To eliminate remote document egress, we introduce HandleMyFile, an edge-native, zero-egress document manipulation architecture executing entirely within client browser threads via isolated Web Worker pipelines. By decoupling interaction orchestration from computation through transferable buffer protocols and enforcing strict Content Security Policy directives (connect-src 'none'), the system guarantees that user documents never transit the network (|Net_out| = 0). Across an empirical benchmark of 490 diverse real-world documents from the standardized Mozilla PDF corpus, we demonstrate that client-side V8 execution achieves near-perfect computational parity with server-side Node.js engines on localhost (delta = 3.52 ms, Cohen's d = 0.0894), while outperforming remote cloud SaaS endpoints across real-world network regimes—scaling from a 1.88x localhost speedup (t(489) = 8.29, p < 0.0001) to an analytical 10.68x speedup on broadband Wi-Fi (up to 14.48x) and 37.86x on mobile 4G (up to 61.97x) due to the total elimination of payload transit penalties. Forensic network packet inspection confirms 0.00 MB outbound transmission across all operational workflows, with 99.71% of catalog and trailer metadata fields purged by its specialized privacy sanitization engine.