Yep, localization is a huge size bloat for enterprisey apps that support many locales. There is no Apple provided way to dynamically download select localization packs based on the device locale. Meta came up with their own solution: https://engineering.fb.com/2022/05/09/android/language-packs...

The small filesize issue is something we commonly see in games, was surprised to see it for Gmail.

And btw we open-sourced much of our analysis after being acquired by Sentry: https://github.com/getsentry/launchpad

130 MB for localization? At 50 languages that would be 2.6 MB/language. If we assume an average 50 bytes per string and another 50 for an identifier, that's 27,000 strings.

That doesn't seem right. Localization feels like it should add a few MB. Not over 100. (Plus shouldn't it be compressed, and locally uncompressed the first time a language gets used?)

Localization doesn’t just mean string translations. Apple platforms give you the freedom to redo the UI to fit the language. For example, parts of System Preferences (not sure about Settings) would look completely different in languages with long words because the original design for English simply didn’t fit. The translators rearranged buttons to make the text fit.

Sure, but that's a few KBs for each locale at most. Still a long way to 100 MB.

They probably just have lots of leftover localized assets that nobody dares to touch as they aren't sure if it's used anywhere.

Thank you! I've been wondering about exactly this, your explanation makes complete sense.

I just looked. In this case, it is just string translations.

In the version I'm looking at there are 27,470 .strings files totaling 69 MiB, but they take up 155.9 MiB of disk space due to the 4 KiB filesystem block size.

The keys for the strings take up 39% of the space while the values take up 61%. About 12% of translations are duplicated (the word "Cancel" is translated like 53 times)

So 55% of the space used for strings localization is just pure waste due to having so many small files. The long keys are rather wasteful too and about 12% of the translations are duplicated (i.e. the word "Cancel" is translated 50+ times per language).

Honestly, it just looks like no one cared.

The version I'm looking at has 27,470 strings files, mostly of them less than 4 KB each.

Since the iOS filesystem uses 4 KB blocks, it looks like about half the space is just wasted.

It probably isn’t just text that is localized.

Any rtl language will probably require a lot of different assets. If for no other reason than gradients. Plus anything asymmetric.

images also may need localization.

Wonder if it is better to create separate localized app download such as gmail-japanese, etc.

Google Play offers such functionality already, it's called App Bundles. Instead of uploading an entire APK, the developers can upload the app assets that get bundled into device-specific APKs containing only the resources necessary for the end device. So you'd only get native libs for your phone CPU architecture, translations for the device language and image assets matching the device resolution for example. In fact, I think it's mandatory now to use the app bundles format (but you're still free to configure it to some extent)

I now see the article is about iOS app, but it looks like the Android app is anywhere between 50mb and 100mb (depending on the apk download side I look at) which is much more reasonable

4kB is also the minimum file size on Linux, so I imagine a similar issue could exist on Android.

The Gmail app on Android is 150MiB in size.

Android traditionally puts resources into a compressed archive, though, so by simply using an archive for storage, Google may be avoiding the 4k size problem.