Back to feed
Dev.to
Dev.to
7/25/2026
I got tired of uploading my HEIC photos to random servers, so I built a WASM-powered client-side converter

I got tired of uploading my HEIC photos to random servers, so I built a WASM-powered client-side converter

Short summary

The author built a fully client-side HEIC converter using WebAssembly and Web Workers, eliminating the privacy risk and bandwidth cost of uploading photos to remote conversion servers. The tool offers three pipelines: HEIC to JPG for web assets, lossless HEIC to PNG for design workflows, and HEIC to PDF for document archiving. A key technical detail is the Web Worker logic that dynamically selects the highest-resolution frame from multi-frame HEIC containers, avoiding the common pitfall of exporting a blurry thumbnail.

  • •100% client-side HEIC conversion using WASM via libheif-js — no uploads, works offline
  • •Web Workers prevent UI freezing during heavy decode operations
  • •Dynamic frame selection logic picks the highest-resolution image from multi-frame HEIC containers

Generated with AI, which can make mistakes.

#ai-tools#open-source
Read full article at Dev.to

Is this a good recommendation for you?

Comments

Failed to load comments. Please try again.

Explore more

I Built a File Converter That Handles 16 Formats in the Browser — No Upload Required
Dev.to
The original title is "Building a Privacy-Friendly Image Converter in the Browser"
Dev.to
I Built a Free Browser-Based File Converter Using WebAssembly — No Uploads, Ever
Dev.to
Why We Built a Browser-Based File Converter Instead of Another Cloud Service
Dev.to