Build file tools that never

Short summary

When building file tools, keep heavy processing on the client with Canvas API, Web Workers, and OffscreenCanvas—they're cheaper, faster, and users trust them more with privacy. Server processing is still needed for video/audio transcoding and OCR, but follow the rule: process, then delete immediately. The author built Filuni (121 file tools) this way and found it unexpectedly cheaper to operate and faster for users than traditional upload-based tools.

• •Client-side processing with Canvas, Web Workers, and OffscreenCanvas keeps user files private and reduces server costs
• •Offload only what the browser can't handle (video transcoding, OCR, Office docs) and delete files immediately after processing
• •Privacy messaging is a differentiator—users notice and respond positively to 'your file never leaves your browser'

Generated with AI, which can make mistakes.