Archive.png This article or section documents a feature not included in the current version of Scratch (2.0). It is only useful from a historical perspective.
This article or section documents an outdated version of Scratch (version 1.4). For this article in the current version, see Project Compression.


When uploading Scratch projects to the Scratch Website prior to Scratch 2.0, the file size for sharing was limited to 10 megabytes (10,240 kilobytes). This was to reduce the amount of space taken up on the servers. Because of the very limited size, users were given the option to compress their project in the Scratch 1.x editors. Compression is the process of lowering the quality of mainly sounds and images to reduce the file size. Sounds can be lessened in size by having lower bit rates, for example, while images can utilize a different color scheme.

The main cause of users exceeding the limit, however, was specifically that Sound files are likely huge; the same applies to large or high quality images. Although Scratch by default would compress the files somewhat, it will not drastically reduce file size.

Basic Method

The "Compress sounds and images" option.

Most users prefer this method of compressing.[citation needed] To do this, users open the "Share" window and check the "Compress sounds and images" option. This will automatically compress sound and image files.

Advanced Method

Other users prefer using the "Advanced Method". This method allows for a more specific compression. This may be used at times when a Scratch project's file size is just over the limit, or users only want to compress sounds or images.

To use this feature, one must click on the "Edit" menu; there are various options. Look for the two labeled "Compress sounds..." and "Compress images...". If one clicks on "Compress sounds..." they will be given four different quality options:

  • High (biggest) - this option reduces the sound filesize by 68.75% [citation needed]
  • Normal - this option reduces the sound filesize by 75%
  • Low - this option reduces the sound filesize by 81.25%
  • Lowest (smallest) - this option reduces the sound filesize by 87.5%

If one clicks on "Compress images..." a box appears with text reading "JPEG Quality (10-100)?". Depending on the chosen number, any images that have been imported into Scratch will have their quality adjusted to the specified parameter.

Note Caution: Compressing images may slightly change the colors which can have an effect on color sensing. Some blocks may need to be modified afterwards.