I Built an Image Compressor That Runs 100% in the Browser

Short summary

Build a client-side image compressor in ~30 lines of JavaScript using the Canvas API, keeping images private with zero server uploads. Drop a file, load it as a Blob, render to canvas, and use toBlob() with quality 0.7 to achieve 50%+ compression while preserving visual quality. The same FileReader → Image → Canvas → Blob pipeline works for resizing, format conversion, cropping, and watermarking—entire image-tool categories can run without a backend.

• •Client-side image compression using Canvas API (30 lines of JS)
• •Images never uploaded to server—privacy is a real feature, not just marketing
• •Same pattern enables resizing, format conversion, cropping, watermarking without backend

Generated with AI, which can make mistakes.