HugeHard StudioPractical guides

Image processing

How to compress an image to a target size

Written and maintained by HugeHard Studio · Updated 14 October 2026

A target is a value to try, not a guarantee for every format or source image. After compression, use the result screen’s actual file size, format, and pixel dimensions as your reference.

Steps

  1. In This Pic Can Change, open Tools (“工具”) → Image Compression (“图片压缩”), then import an image from Photos or Files. Processing happens on device and does not overwrite the original.
  2. Set a target size and choose an output format. The target is adjusted in whole KB, or in whole bytes when the source image is smaller than 1 KB; its range is limited by the imported file’s size. Turn on “Keep original size” (“保留原尺寸”) to preserve pixel dimensions. If it is off, you can choose output dimensions.
  3. Read the format-specific note. JPEG and HEIC search encoding quality to try to keep better quality within the target byte count. This does not guarantee the target will be met. When a transparent image is converted to JPEG, transparent areas are filled with white.
  4. For a GIF, keep the animated format. All frames, frame delays, and the loop count are preserved. If you enable target-size compression and the target is still missed, turning off “Keep original size” lets the app try reducing the dimensions while preserving animation timing.
  5. PNG uses lossless encoding. It does not reduce image quality to make the file smaller, so the output may remain above the target.
  6. Check the result preview for actual file size and pixel dimensions, then save to Photos or share. If the target is missed, the result screen shows the actual size and an explanation.

Check the file before sharing

Confirm the required format, pixel dimensions, and actual byte size. If an email or website has a file limit, check the exported file itself. If PNG or a full-size GIF is over the target, consider allowing a smaller output dimension or choosing a format that suits the material and use. Compression writes a new file and leaves the source unchanged.

Read the product overview or support page, or continue with the video-to-Live-Photo guide and screenshot-delivery guide.