Others

BFCache

Back/forward cache (or bfcache) is a browser optimization that enables instant back and forward navigation. It significantly improves the browsing experience for users-especially those with slower networks or devices.

Back/forward cache

Back/Forward Cache: What It Is and How to Use It to Serve Content Immediately

Image Compression / Compress Image / Image Tools

ImageMagick

brew install imagemagick

mogrify -format jpg -quality 50% /path/to/folder/abc.png

mogrify -format jpg /path/to/folder/*.png

mogrify -format jpg -quality 50% *.png
mogrify -format jpg -quality 50% *.png && rm *.png

mogrify -quality 20% /path/to/folder/*.jpg

mogrify -quality 50% *.jpg
mogrify -quality 10% *.jpg
mogrify -format jpg -quality 50% *.jpeg

# Reduce: If you set a lower quality value (e.g., `-quality 50`), the image file size is reduced by increasing compression. This may lead to a loss in visual quality (e.g., pixelation or artifacts), but the image becomes lighter and faster to load.

# Leave (High Quality): If you set a higher quality value (e.g., `-quality 90` or `-quality 100`), the image retains more detail with minimal compression. This ensures better visual fidelity but results in a larger file size.

# convert pdf to images
convert input.pdf output.jpg # deprecated
magick input.pdf output.jpg
magick convert input.pdf output.jpg

# For good quality use these parameters
magick convert -density 300 -quality 100 in.pdf out.jpg

# resize image to width 25, keeping aspect ratio
magick convert -geometry 25x src/image1.png out/image1.png
magick convert -geometry 600x src/image1.png out/image1.png

# resize image to height 25, keeping aspect ratio
magick convert -geometry x25 src/image1.png out/image1.png

# [ImageMagick - Command-line Tools: Convert](https://www.imagemagick.org/script/convert.php)

Script - PNG to JPG Conversion, Resizing, and Compression

#!/bin/bash

# Set maximum dimensions for resizing (e.g., width=1000px, height=650px)
max_width=1000
max_height=650

# Initialize loop counter
counter=0

# Loop through both PNG and JPG files
for file in *.png *.jpg *.jpeg; do
  # Check if the file exists and is a regular file (not a directory)
  if [ -f "$file" ]; then
    # Increment the loop counter
    ((counter++))

    # Get the current file size in bytes (macOS compatible)
    original_size=$(stat -f %z "$file")

    # Check if it's a PNG file and convert it to JPG
    if [[ "$file" =~ \.png$ ]]; then
      # Convert PNG to JPG with quality 50, save it with the same name but a .jpg extension
      magick "$file" -quality 50 "${file%.png}.jpg"
      # Remove the original PNG file after conversion
      rm "$file"
      # Set the filename to the new JPG file for further processing
      file="${file%.png}.jpg"
    fi

    # Get the current image dimensions (width x height)
    dimensions=$(identify -format "%wx%h" "$file")
    width=$(echo $dimensions | cut -d 'x' -f 1)
    height=$(echo $dimensions | cut -d 'x' -f 2)

    # Resize image while maintaining aspect ratio
    if [ "$width" -gt "$max_width" ]; then
      # Calculate new height while maintaining aspect ratio
      new_height=$((max_width * height / width))
      magick "$file" -resize "${max_width}x${new_height}" "$file"
    elif [ "$height" -gt "$max_height" ]; then
      # Calculate new width while maintaining aspect ratio
      new_width=$((max_height * width / height))
      magick "$file" -resize "${new_width}x${max_height}" "$file"
    fi

    # Optimize image with quality set to 50
    mogrify -strip -interlace Plane -quality 50 "$file"

    # Get the new file size (macOS compatible)
    new_size=$(stat -f %z "$file")

    # Compare sizes and keep the smaller one
    if [ "$new_size" -ge "$original_size" ]; then
      echo "[$counter] Skipping $file, new size is not smaller."
    else
      echo "[$counter] Processed $file successfully."
    fi
  fi
done

imagemagick

GitHub - kornelski/pngquant: Lossy PNG compressor - pngquant command based on libimagequant library

jpegoptim

Description: A tool specifically for optimizing JPEG images. It supports both lossy and lossless optimization.
Compression Method: Lossy and lossless.

# installation
brew install jpegoptim

# Compresses all JPG files to a maximum quality of 75% while preserving EXIF data.
jpegoptim --max=75 *.jpg

# Maximum Compression
# --strip-all - Strips all metadata (e.g., EXIF, comments, color profiles) to reduce file size.
# --all-progressive - Converts images to progressive JPEGs, which are better for web and often smaller.
jpegoptim --max=75 --strip-all --all-progressive *.jpg

GitHub - tjko/jpegoptim: jpegoptim - utility to optimize/compress JPEG files

mozjpeg (via `cjpeg`)

Description: A JPEG encoder that offers excellent lossy compression with reduced file sizes.
Compression Method: Lossy.

# installation
brew install mozjpeg

# Compresses `original.jpg` into `compressed.jpg` with 75% quality.
cjpeg -quality 75 -outfile compressed.jpg original.jpg

# Maximum Compression with Optimized Huffman Tables
cjpeg -quality 85 -progressive -optimize -tune-psnr -outfile temp.jpg

GitHub - mozilla/mozjpeg: Improved JPEG encoder.

ImageOptim CLI

Description: A macOS-friendly tool that focuses on lossless compression, preserving image quality while reducing file size.
Compression Method: Lossless.

# installation
brew install imageoptim-cli

# Compresses all JPG files with a focus on smaller file sizes.
imageoptim --quality-low *.jpg

GitHub - mozilla/mozjpeg: Improved JPEG encoder.

MozJpeg - Compress/edit images online.

jpegtran

Description: A lossless JPEG compressor that rearranges file structure for optimal compression.
Compression Method: Lossless.
Installation:

brew install jpeg
Example Command:

jpegtran -optimize -progressive -outfile compressed.jpg original.jpg
- Optimizes and converts the image to a progressive JPEG format.

Recommendation

Use ImageMagick or jpegoptim if you want flexibility between lossy and lossless compression.
Use mozjpeg for maximum reduction in file size with excellent visual quality.
Use pngquant for png images

BFCache​

Image Compression / Compress Image / Image Tools​

ImageMagick​

Script - PNG to JPG Conversion, Resizing, and Compression​

jpegoptim​

mozjpeg (via cjpeg)​

ImageOptim CLI​

jpegtran​

Recommendation​