Dokdoin - Convenient & Safe Web Tools

Image Compressor

The Image Compressor (Optimization) tool is a security-friendly utility that significantly optimizes high-quality image sizes with a single click, without requiring software installation or sign-ups. It runs entirely in your browser, ensuring zero risk of image leaks.

Drag and drop the image to compress here
Or click to select a file or paste a clipboard image (Ctrl+V).
Compression and format setting options
Compression quality (Quality)
Output format (Format)

Smart Image Size Reducer (Compression/Optimization) Guide and Tips

The image size reducer (compression/optimization) tool is a security-friendly utility that significantly optimizes the size of high-quality images with a single click, without the need for installing any programs or signing up. It runs in the browser, so there is absolutely no concern about image leaks.

Precautions for Use

  • JPEG vs. WebP format recommendation: To improve website or blog loading speed, saving in the latest high-compression WebP format is highly recommended. Choose JPEG if universal compatibility is required.
  • PNG transparency preservation: When compressing a PNG file with a transparent background (Alpha channel) to JPEG, the background will be filled with black or white. To maintain transparency, make sure to specify PNG as the output format.
  • Limitations of in-device local computation: Since this tool computes 100% on the browser's memory without sending photos to a server, loading multiple huge photos of several tens of megabytes at once may slow down the browser.

Key Features

  • Security-focused internal computation: The registered image assets are directly optimized within the device, allowing you to safely compress personal photos or captured images of internal confidential documents without fear of network leakage.
  • Lossless-grade optimization: Setting the quality option to around 80%~90% allows you to save image file size from 50% up to over 90% while visual quality degradation is practically indistinguishable to the naked eye.

How to Use

  1. Drag or click the upload area to load the image files you want to compress. Pasting clipboard images (Ctrl+V) is also supported.
  2. Adjust the quality slider to select the desired image quality. (The default value of 80% is highly recommended.)
  3. After checking the output format and quality options, click the 'Download Compressed Image' button to save it to your device.

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