Translations missing key elements, such as a variable or link, could break your website or app. To help prevent this, Transifex automatically checks every translation against a set of conditions.

Whenever a condition is not met, e.g., an HTML element is missing, the translator will be shown either a warning or an error message telling them what needs to be fixed. Translators can still save a translation when there's a warning. But if there's an error, they must address the issue before saving the translation.

Each file format has a set of translation checks by default. You can change whether a failed check results in an error or warning or turn off a check altogether. You need to have an administrator role to perform the following changes.

To customize translation checks:

You can always restore the translation check settings by clicking the Set to default checks next to the Save button.

If you use custom variables in your code, you can set up custom translation checks and make sure they are left untouched in the translation. This is done by adding a custom check for a file format and specifying either the characters your custom variables start and end with or the exact characters your variables consist of.

To do this:

Like the default checks, you can change whether a failed check results in an error or warning or turn it off altogether.

With custom translation checks, you, as an organization administrator, can add your own regular expressions and ensure that nothing will break your website or application due to an invalid translation.

These checks can be created per file format as follows:

When the source text contains double or single quotes, and you want to check that there are quotes also in the translation text, you can use the following regular expression:

Regex: \"|\'

You can omit the double or the single quote from this regex if you want to check only for one of them, e.g. \"

This expression instructs the system to find if double or single quotes exist in the translation text. Depending on where this check will be applied, translations only or both source and translation string, the following can happen:

The setup will look like this:

Your regex expression can easily be tested using the test area.

Message returned when translation check fails:

Message returned when translation check is successful:
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More examples can be found below:

You can use the following regular expression to check whether there are characters apart from alphanumeric ones and whitespace in the translation text or both the source and translation texts. Special characters include: !@#$%&* and others.

Regex: [^a-zA-Z0-9\s]

Often, translators add a space, tab, or newline at the end of their translation text, which is not present in the source text. You can use the following regular expression to check whether there are such cases.

Regex: [\s\t\n]+$

Using the + in the regular expression means there will be a match even if spaces, tabs, or newlines are more than one. The $ sign denotes the end of the string. If you apply it to both the source and the translation text, then the following can happen:

If the check is applied only to the translation text, an error will be raised every time there is a space, tab, or newline at the end of the string, regardless of whether the source text contains them.

Like the example above, if you want to locate whitespace at the beginning or the end of a string, you can use the following regular expression.

Regex: ^\s+|\s$

The | sign is used as the logical OR, and the ^ sign marks the beginning of the string. If you apply this check to the translation text, for example, the following can happen:

Often, source strings contain inline formatting. This formatting usually needs to be applied to the translation text, too. If you want to ensure that your translators preserve the formatting of words emphasized in the source language when translating content, then you can use the following regular expression.

Regex: \*\*

When this check is applied to the translation and source strings, the following can happen:

Sometimes, the translators accidentally add more than one whitespace in their translations. To catch such cases, you can use the following regular expression.

Regex: \s{2,}

The curly brackets signify how many times the previous token, in our case the whitespace, is repeated. The lower limit is two times; there is no upper limit. When this check is applied to the translation text, the following can happen:

The source text often contains variables the translator should leave intact while translating the source string. If whitespaces are added by mistake, the developers' code will break, and the app or page might not load correctly.

Let's take, for example, the following source string: "There are %no_of_countries% in %continent%". The translator adds the following as a Greek translation: "Υπάρχουν %no_of countries% χώρες στην %continent%". There is a whitespace added by accident in the first variable. When the following regular expression is used, these mistakes can be corrected before the translations reach production.

Regex: %(?!%)(?!%)\S+?%

The negative lookaheads (?!%) denote that the first character, the %, should not be followed directly by one or two of the same characters. It should be followed by one or more non-whitespace characters and end with the % character.

Given the example above, and considering that you have a translation check with the above regular expression configured for both the source and the translation text, an error (or a warning) will be raised for the translation entered.

When you want to identify instances where any character except a list of excluded characters is enclosed in brackets, you can use the following regular expression.

Regex: \[([^w|W])\]

To match any character except a list of excluded characters, put the excluded characters between [^ and ]. The caret ^ must immediately follow the [.

When this check is applied to the translation text only, the following can happen:

You can use the following regular expression to identify instances where translation text contains consecutive duplicate words.

Regex: \b(\w+)\s+\1\b

The \b character is a word boundary that allows you to perform a “whole words only” search. For instance, regexp \bJava\b will be found in Hello, Java!, where Java is a standalone word, but not in Hello, JavaScript!.

The \w+ character matches word characters. A word character is a character a-z, A-Z, 0-9, including _ (underscore). The parentheses around this group of characters create a capturing group, which allows you to refer to the matched characters later in the expression.

The \s+ character matches one or more whitespace characters (such as a space, tab, or newline).

Finally, the \1 at the end of the expression matches exactly the same text matched by the first capturing group.

When this check is applied to the translation text only, the following can happen:

When you want to check if both source and translation text end with a colon(:), you can use the following regular expression.

Regex: ^(?!.*:$).*$

When this check is applied to translations and source strings, the following can happen:

To check if the translation accurately reflects the style and tone of the original text, you can use a regular expression to identify words or phrases that shouldn't be there in the first place. For example:

Regex: \b(yo|dude|bro)\b

When this check is applied to translations only, the following can happen:

On-demand translation checks can be found under the settings page of your Transifex project. This feature allows you to run translation checks on translation strings that have already been submitted.

To run translation checks on demand, you need to:

When the task is completed, an email notification will be sent to the user who performed this action (admins, maintainers) where a detailed report will be included: