How many keywords can I use ?
Keywords form part of the indexable metadata on both the App Store and Android Play Store. Much like metadata keywords, they help users find your app by using commonly used terms.
Keywords in iTunes Connect (iOS Apps)
While there is no limit on the number of words, there is a character limit – and this is quite conservative! You can enter up to 100 characters, which includes the separating commas. We recommend not using spaces between your keywords in order to save space.
It is against App’s guidelines to use profanity here and over using commonly used terms (e.g. Sex) will be removed (see Section 3.9 of the App Store Review Guidelines)
Keywords in the Android Play Store
There is no official way to tag or keyword your metadata in the Play Store. Instead, Google uses a special algorithm to look at your App Store Description and automatically picks keywords for your app.
Inserting “Keywords: cat, dog, mouse, etc” into your App Store Description will be flagged as spam!
MobiLoud shares 5 Ways To Optimise Your Android App on Google, reporting best practice is to include what you consider your main keyword in the App Title and again five times throughout the description.
A distinction must be made here between localization and translation. Translating your keywords may not be enough. For example, what we officially call a television remote control in each country may be one thing, but what we colloquially call it will be another. Keywords must reflect these differences as they need to ensure that they are relevant to the end user searching for the app. Therefore, we recommend localizing, not translating, keywords.
It is also very important to note that words in all languages are different lengths. The general rule is to leave 30% space, but with keywords, this can be tricky. You may need to accept that in languages with traditionally lengthier nouns (e.g. German, Russian) that one or two keywords may need to be left out. Choose your keywords wisely – or ask for advice from a native speaker.