1. Biyaoyun Image Tool
    A versatile batch processing tool that allows image compression, format conversion, resizing, and watermarking without uploading files. Supports various formats.
  2. TinyPNG
    An online tool for compressing PNG and JPEG images while maintaining high quality.
  3. JPEG-Optimizer
    Specializes in compressing JPEG images with customizable compression levels.
  4. ImageOptim
    A free, open-source tool for macOS that losslessly compresses PNG, JPEG, and GIF images.
  5. Compressor.io
    An online tool that effectively compresses PNG, JPEG, GIF, and SVG images.
  6. Kraken.io
    An online tool offering various compression modes and batch processing.
  7. Optimizilla
    Supports batch uploading and compressing of JPEG and PNG images online.
  8. JPEGmini
    Designed for JPEG images, offering efficient compression algorithms.
  9. Caesium
    An open-source Windows tool for batch image compression.
  10. RIOT
    A lightweight Windows application that allows real-time compression preview.
  11. PNGGauntlet
    Specializes in PNG image compression using multiple optimization tools.
  12. FileOptimizer
    A Windows utility that optimizes images, PDFs, and other file types.
  13. Compressnow
    An online tool supporting JPEG, PNG, and GIF image compression.
  14. Squoosh
    An online image compression tool by Google, supporting multiple formats.
  15. Trimage
    A Linux tool that losslessly compresses PNG and JPEG images.
  16. XNConvert
    A cross-platform image conversion and compression tool with batch processing capabilities