A few thoughts on the importance of file size...
Reasons to keep content small
Download time: Nobody wants to wait a long time. If readers need to wait too long, they might get annoyed and cancel the download. They might even delete your app, because of the huge download time... Keeping content file size small is all about keeping readers satisfied. See the comparison table below for average download times based on the download speed.
Device space: Not every reader has that state of the art device with 250GB of storage. In fact, a lot of readers still have devices with 16GB or 32GB of storage. So, if you want them to read your content, understand that readers need to be selective in terms of saving content on their devices and reader don't want to clean up content all the time...
Average Download Times
|100||3m 20s||1m 40s||50s||25s||16s||8s|
|450||15m||7m 30s||3m 45s||1m 52s||1m 12s||36s|
|700||23m 20s||11m 40s||5m 50s||2m 55s||1m 52s||56s|
|1500||50m||25m 30s||12m 30s||6m 15s||4m||2m|
Download times are average download times. Actual speed is often influenced by a lot of additional factors. Realistically, the times above should be multiplied by 4 or 5.
Tips to keep your content small
- Choose to work article-based instead of the legacy issue-based approach. Article-based applications work with Content Items, where the reader doesn't need to download bulky issues but only downloads content on demand. You can find more info here.
- Movies are a lot of fun. Make sure your movies are optimised and – if possible – avoid embedding movies in your app. Use streaming instead. See the following articles for more info about using video:
- Optimize your PDF-files. That's not only important for colors (cmyk vs. rgb) but also very important for the file size: downsampling pictures is a must! See Optimising PDF's for viewing on mobile devices.
- Custom Fonts are a nice way to give your article-based application a nice design. But make sure you only upload fonts you really plan to use. All uploaded fonts will have to be downloaded in the app when the reader starts it up for the first time. More info.
- Check all your other resources and make sure your Web Resources folder doesn't contain any files that aren't used:
- The most important thing remains: Testing. Test your creations, test your applications, test the content etc. And then test again and once more to be sure.