What is Image Compression?
Image compression reduces a file's size while aiming for minimal quality loss. Smaller files load faster, consume less storage, and noticeably improve your website's performance.
There are two fundamental approaches: lossy and lossless compression. Lossy compression removes image information that the human eye barely perceives. Lossless compression reduces file size through clever encoding without changing a single pixel.
Formidex compresses your images directly in the browser using the Canvas API and supports output as WebP, JPEG, and PNG. A quality slider lets you control the balance between file size and image quality.
How does Image Compression work?
The quality slider controls how aggressive compression is. For JPEG and WebP, a lower value removes more visual detail and produces smaller files. A value around 75 to 80 percent offers the best trade-off between quality and size for most uses.
The WebP format often achieves 25 to 35 percent smaller files than JPEG at the same visual quality. All modern browsers now support WebP, making it the best choice for web content in most cases.
Tips for best results
For photos on websites, WebP at 75 to 80 percent quality is a good starting point. Files are significantly smaller than JPEGs without visible differences to the naked eye.
Use PNG only when you need transparency or for graphics with few colors and sharp edges, such as screenshots or logos. For photos, PNG is unsuitable due to large file sizes.
Compare the compressed version with the original before using it. Over-compression creates visible artifacts, especially around edges and in gradients. When in doubt, compress a little less.
Common use cases
Optimize web performance: Google evaluates loading speed as a ranking factor. Compressed images are one of the most effective levers for improving page speed. Total page size can often be reduced by 50 percent or more.
Save storage space: photo libraries and media archives grow quickly. Compression can significantly reduce required storage without noticeable quality loss.
Emails and messengers: many services have file size limits for attachments. Compression lets you send images that would otherwise exceed the limit without having to resize them.