How we built a browser image compressor that never makes files bigger

说明与用途

完全在客户端运行的图像压缩器，保证文件大小不增大，并将结果打包为 ZIP。

问题

Ensuring that a browser‑side image compressor never increases file size while supporting multiple formats and preserving user privacy.

结果

The compressor processes images entirely on the client, never enlarges files, and provides a ZIP of results, preserving privacy and performance.

工作流

• Select or drag‑drop images
• Choose target format or keep automatic
• Set quality and resize options
• Compressor decodes with createImageBitmap
• Generates candidate encodings (WebP, JPEG, PNG)
• Selects smallest blob that is smaller than original
• Returns original if no smaller candidate
• Packages results into a ZIP via JSZip
• Downloads ZIP or individual file

证据

Our compressor accepts a batch, starts processing immediately, and returns either a smaller encoding or the original file.

来源

The size guarantee belongs after candidate selection. It must also apply after resizing, forced conversion, and preprocessing.

来源

Each worker receives a file, options, and a job identifier. It returns either the result or an error carrying that identifier.

来源