How to Localize Forms, Buttons, and Error Messages

Principles of UI localization

UI localization has certain features that should be considered before starting any localization project.

Firstly, it is essential to define the target audience. The quality of localization will ultimately be evaluated by the users of the interface rather than by linguistic experts. For them, the translator’s erudition or stylistic elegance is far less important than the clarity and functionality of the interface.

From this, we can derive the first principle: maximum accuracy and clarity of localization. The translated text must be concise, precise, and easy to understand. This usually means prioritizing commonly used words, appropriate terminology, and consistent phrasing over complex or stylistically elaborate constructions.

Secondly, interface elements such as buttons, forms, and error messages often have a limited window size that can only accommodate a certain number of characters. When translating, you should stick to the number of characters in the original as much as possible, because a longer translation may simply be cut off or, worse, break the display of the element in the interface.

Thirdly, since interface elements are interconnected and refer to each other, it is important to maintain consistency in translation. This is especially important in error messages, which frequently refer to specific interface elements. If the terminology is inconsistent, users may struggle to identify the source of the problem. For this reason, glossaries, style guides, and translation memory tools are widely used in professional localization workflows.

Finally, unlike structured texts such as books, manuals, or brochures, UI translations typically consist of isolated words or short phrases that lack a continuous narrative structure. Translators often work with strings presented out of context, which makes understanding their function more challenging. In such cases, context becomes critical. Without access to screenshots or a working version of the interface, it can be difficult to determine how and where a particular button, label, or message is used. Given these circumstances, it may be useful to use localization forms that contain information about variables, comments for the translator, length restrictions, etc.

Adapting buttons and labels

• Buttons and labels often contain a single word or short phrase that can be difficult to understand without context.
• Many buttons take the user to different screens/windows of the interface, which may have labels. It is necessary to maintain consistency between the button and the label.
• It is often impossible to tell whether it is a button or a label if there is no additional context. This may not matter for some languages, but sometimes (for example, for the Ukrainian language) the translation may differ because the button text is a verb and the label is a noun.
• Since buttons often consist of a single word, it can be difficult to preserve the length of the word in translation. Sometimes it is necessary to choose a less accurate translation or shorten the word, which reduces clarity.

Localizing error messages

• Error messages are often larger than buttons or labels, so there is more space for the translator to translate and match the length of the original text.
• Often, the error message text refers to some other element of the interface, so it is extremely important to maintain consistency in translation.
• Error messages may contain placeholders or variables, so it is worth checking that the translation takes these circumstances into account.

Common mistakes and pitfalls

Below are the most common UI localization problems you may face.

• The translated text is much longer than the original and breaks the window display.
• Improper or missing plural rules.
• Incorrect formatting of dates, times, numbers and currencies.
• Often there are no equivalents for the term in the target language.
• Incorrect translation due to lack of context.
• Unescaped placeholders or broken variables.
• Lack of RTL support, causing layout mirroring or alignment errors.
• Unclear translation due to the translator's own artistic vision.

Recommendations for translators and designers

A skilled translator can take into account all the complexities and nuances of UI localization and deliver a high-quality result. However, many potential issues can and should be prevented at the website or application design stage. Effective collaboration between designers and translators significantly improves the localization process and ensures that the final product provides a seamless and intuitive user experience across different languages and cultures.

Below are practical recommendations for designers and translators.

Recommendations for designers

• Design windows, buttons, and other elements with window scaling in mind. If the translation is longer than the original, the window will simply expand to accommodate the necessary text.
• If your UI contains numeric variables with nouns (e.g., “1 file”, “2 files”), keep in mind that different languages may have several plural forms. While English typically has two forms (singular and plural), Ukrainian has 3, and Arabic has 6.
• Choose fonts that support multiple writing systems. Not all fonts support non-Latin scripts. If the product is intended for international markets, select fonts that include extended character sets, such as Cyrillic, Arabic, or East Asian scripts.
• Design your UI with right-to-left languages in mind.
• Avoid embedding text in images. Text that is hard-coded into images complicates localization and increases development time. Instead, use editable text layers or externalized strings whenever possible.

Recommendations for translators

• If possible, open the website or application you are translating, or ask the customer for screenshots to understand where the element is located and what it is used for. Understanding the context significantly improves the quality of the translation and the user experience.
• Try to stick as closely as possible to the length of the original text. Even if the developer has taken care to scale the window size, the text should still be close to the original so as not to spoil the look of the design. To do this, you can sometimes omit unnecessary words (e.g., please) or shorten words.
• Pay special attention to variables and plural forms. Carefully check how numeric variables are structured. If the system does not properly account for different plural forms, consider adapting the phrasing to avoid grammatical errors. In some cases, restructuring the sentence, shortening the noun, or separating the number and the noun with punctuation (such as a colon or brackets) can provide a practical solution.
• Ensure terminological consistency. Use glossaries, style guides, or translation memory tools to maintain consistent terminology across the interface. Consistency enhances usability and prevents confusion.

Also, the presence of a localization form that contains information about variables, comments for the translator, and length restrictions greatly simplifies the work for the translator and improves the quality of the final localization.