Frequently Asked Questions


Question: What file formats does it support?

Answer: Compresss.com is a one-stop website for developers to compress all kinds of files used on website:

  • Image: JPG, PNG, GIF, SVG, WEBP
  • Document: PDF, WORD


Question: Is it safe to compress files on Compresss.com?

Answer: Yes, it's safe to compress files on Compresss.com. All your files are treated as strictly confidential. All file transmissions are through HTTPS instead of HTTP. Your files will be saved to a directory with random 10 characters so only you can find it. Your files are only temporarily stored on our servers for 1-2 hours, after that they will be automatically deleted by a scheduled program.


Question: What are the file limits?


  • File count: no limits
  • File size: 40m each at max
  • File extension name allowed: .htm, .html, .shtml, .css, .js, .json, .xml, .jpg, .jpeg, .jpe, .png, .gif, .svg, .webp, .pdf, .doc, .docx, .docm, .dotx, .dotm, .dot, .rtf, .odt, .ott, .fodt, .uot, .eml
  • Number of files compressed simultaneously: 2


Question: I compressed lots of files. How can I download all compressed files at once?

Answer: You can compress all output files in a ZIP file by clicking "" icon on the right of "Output Files" section and clicking "Add to ZIP" on the pop-up menu. To download the zip file, simply click on it or right-click on the ZIP file link and click "Save link as...".


Question: Why is the file size not reduced after compression?

Answer: The file may be compressed before or has lower quality than settings. For example, changing a JPG file's image quality to 80 will not reduce file size if the JPG file's original image quality is 80 or lower.


Question: Can I submit a ZIP file which contains all website files?

Answer: We are working on supporting zip file, so you only need to pack your website in a zip file and our site will compress every website files in this zip file. This function is in beta testing, please check back later.


Question: I have more questions, who should I write to?

Answer: Please send your additional questions to nospamplease@163.com and will usually get response in one business day.