Image compression in practice: taking into account file size and clarity

Process size before compression

The main reason for large files is the pixel size, not the quality setting. If the image will only display a maximum width of 1200 pixels on the web page, there is no need to upload the 6000 pixel original image. First scale according to the actual display size, and then start compressing.

Select the format according to the content

Photos are usually suitable for WebP or JPEG; use PNG or WebP when a transparent background is required; images and text screenshots should give priority to retaining edge clarity. If you choose the wrong format, it will be difficult to balance size and effect no matter how you adjust the quality.

Find a balance with small adjustments

Adjust only one factor at a time: for example, fix the width first, and then gradually reduce the quality. When comparing, please look at the actual display size and 100% magnification, paying special attention to faces, text edges, gradients and high-contrast areas.

Pre-delivery checklist

• File names are meaningful and do not contain blanks or sensitive information.
• It can still load quickly under mobile networks.
• No obvious color banding, squares, or text blur due to compression.
• Keep the original uncompressed file for later re-export.

Conclusion

Effective compression is not a blind pursuit of the smallest file, but allows users to quickly see clear content under the required device and network conditions.