Ultimate Guide to Image Optimization for Blazing-Fast Website Performance

Updated at: 17/07/2025

Slow image loading crushes website speed and user experience. This ultimate guide provides a comprehensive toolkit for optimizing images, dramatically improving your website's performance. Learn how to choose the right image formats, compress images without sacrificing quality, and implement effective lazy loading. Prepare for blazing-fast load times and a boost in user engagement!

Methods: Affinity Photo & Squoosh.app Combo for Optimized Images

Step-by-Step Instructions

  1. Prepare Image in Affinity Photo

    • Open image in Affinity Photo, copy the image (Cmd+C/Ctrl+C).
    • Create a new document in Affinity Photo with desired dimensions (e.g., 2560x1706 pixels, 144 DPI). Paste the copied image (Cmd+V/Ctrl+V) and resize to fit without cropping.
    • Export as JPEG in Affinity Photo, adjusting the quality slider to aim for under 1MB. (Initially aim for quality around 90)
    Export as JPEG in Affinity Photo, adjusting the quality slider to aim for under 1MB. (Initially aim for quality around 90) Export as JPEG in Affinity Photo, adjusting the quality slider to aim for under 1MB. (Initially aim for quality around 90)
    Prepare Image in Affinity Photo

  2. Optimize Image with Squoosh.app

    • Upload the exported JPEG to squoosh.app.
    • Select WebP format in squoosh.app and adjust the quality (around 85) to achieve a significantly smaller file size. Aim for under 200KB.
    • Save the optimized WebP image from squoosh.app.
    Save the optimized WebP image from squoosh.app. Save the optimized WebP image from squoosh.app.
    Optimize Image with Squoosh.app

Tips

  • Consider using a 16:9 or 21:9 aspect ratio for web-friendly dimensions.
  • Higher resolutions (e.g., 2560x1440 or higher) are better for high-resolution displays.
  • WebP is a modern format that often provides better compression than JPEG.

Methods: Photoshop & Squoosh.app for Optimized Images

Step-by-Step Instructions

  1. Photoshop Image Preparation

    • Open image in Photoshop, copy the image (Cmd+A, Cmd+C / Ctrl+A, Ctrl+C).
    • Create a new document in Photoshop with desired dimensions (e.g., 2560x1706 pixels, 144 DPI). Paste the copied image (Cmd+V/Ctrl+V) and resize to fit without cropping.
    Create a new document in Photoshop with desired dimensions (e.g., 2560x1706 pixels, 144 DPI). Paste the copied image (Cmd+V/Ctrl+V) and resize to fit without cropping.
    Photoshop Image Preparation

  2. Initial JPEG Export from Photoshop

    • Export as JPEG in Photoshop using 'Save for Web (Legacy)', targeting under 1MB. Initially aim for quality around 85.

  3. Squoosh.app Optimization

    • Upload the exported JPEG to squoosh.app.
    • Select WebP format in squoosh.app and adjust the quality (around 85) to achieve a significantly smaller file size. Aim for under 200KB.
    • Save the optimized WebP image from squoosh.app.
    Save the optimized WebP image from squoosh.app. Save the optimized WebP image from squoosh.app.
    Squoosh.app Optimization

Tips

  • Same tips as Affinity Photo method apply here.

Methods: Photopea & Squoosh.app for Optimized Images (Free)

Step-by-Step Instructions

  1. Prepare Image in Photopea

    • Open image in Photopea, copy the image.
    • Create a new document in Photopea with desired dimensions. Paste the copied image and resize while holding Shift to maintain aspect ratio.
    • Export as JPEG in Photopea, targeting around 400KB. Adjust the quality (around 90).
    Export as JPEG in Photopea, targeting around 400KB. Adjust the quality (around 90).
    Prepare Image in Photopea

  2. Optimize with Squoosh.app

    • Upload the JPEG to squoosh.app.
    • Select WebP format and adjust quality (around 85) to further reduce file size. Aim for under 200KB.
    • Save the optimized WebP image.
    Save the optimized WebP image. Save the optimized WebP image.
    Optimize with Squoosh.app

Tips

  • Same tips as Affinity Photo method apply here.
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Common Mistakes to Avoid

1. Using images that are too large

Reason: Large image files significantly increase page load times, negatively impacting user experience and SEO.
Solution: Resize images to the exact dimensions needed for your website and use appropriate compression techniques.

2. Ignoring image file formats

Reason: Using the wrong file format (e.g., using PNG for photos instead of JPEG) can result in unnecessarily large file sizes.
Solution: Choose the most appropriate file format for each image type (JPEG for photos, PNG for graphics with transparency, WebP for best overall compression).

3. Not using lazy loading

Reason: Images above the fold (immediately visible) are loaded first, while images below the fold (only visible after scrolling) are loaded at the same time, slowing down initial page load.
Solution: Implement lazy loading to defer the loading of off-screen images until they are needed, significantly improving initial page load speed.

FAQs

What are the best image formats for web optimization?
For photos, WebP generally offers the best compression with excellent quality. If browser compatibility is a concern, consider using next-gen formats like AVIF (even better compression than WebP) or sticking with optimized JPEGs for wider support. For graphics and logos, PNGs (lossless) or optimized SVGs (scalable vector graphics) are usually preferred.
How can I resize images without losing too much quality?
Use image editing software (like Photoshop, GIMP, or online tools) to resize your images to the exact dimensions needed on your website. Avoid upscaling (making images larger than the original) as this will significantly reduce quality. Save your images at the appropriate resolution for your website (retina displays usually need higher resolution than standard).