Should I use the formal form (~ます) on the buttons of an app?

Question

I'm an iOS app developer who's learning Japanese. I want to localize my app to Japanese (make a Japanese version of it, basically). For context, my app falls into the "Utilities" category on the app store.

In the user interface of my app, suppose there is a button that says "Save". I want to replace the "Save" text with a Japanese translation. I thought of three ways to do this:

1. 保存
2. 保存する
3. 保存します

I'm wondering which one of those I should use. The first one is not a verb since it doesn't have the する at the end. So I guess it doesn't really imply that the button does a "save" action? Does this sound like, in English, when there is a button that applies some settings, instead of "Apply", it says "Application"? I think this is not appropriate, is it?

The second one sounds fine, but is it ok to use the plain form here? Is it too informal to be in a Utility app? Should I use the third instead?

I have seen other apps use the first and second form, like 完了 (the "Done" button) and 投稿する (I saw this in the Facebook app's "post" button). But since Facebook is a Social app, I guess it is ok to use the plain form because it sounds like Facebook is treating you like a close friend.

Which one should I use and why?

Answer 1

I'm actually a developer working for a Japanese programming company.
It might depend on some people, but as far as buttons go.

「保存」、「登録」、「完了」、「キャンセル」

etc. seems like the way to go. Of course your will probably need a confirmation box in which you will usually write in the ます form.

「削除します。よろしいですか？」

It might be more common to write a verb on the button for less obvious/common actions like 「投稿する」

Also, I would probably not use the ます form on a button. If you feel like you have to, する probably seems more natural. It doesn't feel like you have to be polite with a button, it feels like the text on a button is what the client say to you, and not what you say to the client, if that makes any sense.

Answer 2

Please check Microsoft's Japanese Style Guide (for UI), in particular the Style section on Page 46.

Style

Use Desu-masu (ですます調, polite style), Dearu (である調, plain style) and noun phrase (体言止め) appropriately.

When to use Desu-masu: In general, sentences should be translated in Desu-masu unless otherwise instructed. When the sentence prompts users to take an action, use “...してください。”. Example: Explanatory texts in windows, dialog boxes, message boxes and status bar (in software); Explanatory text except for headings (in document)

When to use Dearu: When sentences should be briefly and simply translated, use Dearu. Noun phrase can be used depending on the situation (lack of space, etc.). Make sure to keep consistency on levels. Example: Check box, Option button (in software); Explanatory texts used as headings (in document)

When to use noun phrase: When sentences should be briefly and simply translated, use noun phrase. Dearu and appropriate postpositional particles can be used depending on the situation. Make sure to keep consistency on levels. Example: Titles of menus and boxes, menu commands, labels in dialog boxes, command buttons, tabs, list items in list boxes or combo boxes (in software); Titles of web pages, headings, call-outs, captions (in documents) When using noun phrase, make sure to keep the expression simple and clear.

Example:

Show changes
(+) 変更箇所の表示
(-) 変更箇所を表示

Open an item
(+) アイテムを開く
(-) アイテムの開き Note: Use Dearu instead for clarity

Somewhat related: Why do road signs have 止まれ, not 止まる, 止める or 止めて?

Edit: you can also look up translations of various terms in different contexts on the Microsoft's Language Portal, e.g:

https://www.microsoft.com/Language/en-us/Search.aspx?sString=save&langID=ja-jp

Answer 3

(I have Programming experience) You should not use 保存します.

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Because

In general, Using 保存 or 保存する in Japan. For example, Look at the picture. This is a Twitter(Android)'s window.

It is written 保存. ...and Look at next Picture.

This is a Chrome(This is also android version)'s window. It is written (something)を保存.