Image Converter & Target-KB Compressor
Convert HEIC, WebP, AVIF, PNG & JPG in bulk — or compress photos to an exact KB size.
How to Use Image Converter & Target-KB Compressor
- Drop one or more images (HEIC, WebP, AVIF, PNG, JPG, GIF) onto the dropzone, paste from your clipboard (Ctrl+V), or click "Load Sample Photo".
- Choose your output format (JPG, PNG, or WebP) and optional Target File Size (e.g. "Under 100 KB" for passport/government portals, or use the quality slider).
- Download individual converted images immediately or click "Download All (.ZIP)" to get your entire batch in one archive.
100% Private In-Browser Image Conversion & Exact-KB Compression
Uploading personal photos, ID scans, or client assets to legacy cloud converters exposes your files to remote servers and frustrating daily limits (often 2 files per day). Shoal's Image Converter & Target-KB Compressor processes every pixel inside your browser's local memory using HTML5 Canvas, WebAssembly HEIC decoding, and a binary-search bitrate controller.
How Exact Target-KB Compression Works
Government portals, visa applications, university admissions, and job boards frequently reject photos larger than 50 KB, 100 KB, or 200 KB. Standard sliders make you guess a percentage (like "72% quality") and hope the file lands under the limit. Our Target-KB Binary Search Engine automatically runs up to 7 fast binary-search passes over the quantization matrix (and gently scales dimensions only if mathematically required) to hit your exact kilobyte ceiling while preserving maximum sharpness.
| Format | Best Use Case | Transparency | Browser Compression Efficiency |
|---|---|---|---|
| JPG / JPEG | Photographs, ID portals, email attachments | No (White/custom fill) | High (tunable to exact KB target) |
| PNG | Logos, screenshots, crisp UI graphics | Yes (8-bit alpha) | Lossless |
| WebP | Modern websites, e-commerce speed, blogs | Yes | Superior (25–35% smaller than JPG) |