Integrate RESX

with Localazy within minutes.

To translate RESX files, you can use any text/code editor that supports the format (such as Microsoft Visual Studio and its extension called ResX Resource Manager), copy and paste each value into a machine translation engine of your choice, and create a translated version of your file.

A better way to translate RESX files is to upload it to Localazy - the online translation management system and localization suite that will help you translate your RESX files effectively. Learn more in the Getting Started Guide.

To translate RESX files using the Localazy interface, sign up for free and create a new translation project. Once you upload your RESX file add a new language and start translating! You can even pre-translate the whole RESX file by applying machine translations in bulk.

Managing RESX files manually can be time-consuming and prone to errors, especially when multiple people are involved. Localazy makes this process faster, easier, and more reliable by means of:

• Automated data exchange via CLI for smooth integration into your workflow.
• Automated and machine/AI-powered translations to save time.
• An intuitive interface for making changes without bothering developers.
• A single source of truth for all your RESX files.
• A collaboration platform that connects developers, translators, and reviewers in one place.

Sign up for free, create a project, and upload your RESX files. Localazy helps you scale your translations with ease.

RESX files are a standard way to store localized resources in .NET applications, however, they come with several limitations that make scaling and collaboration difficult.

The technical RESX-specific limitations include:

• XML overhead – the verbose XML structure makes files bulky and harder to review compared to simpler formats like JSON or YAML.
• Poor handling of pluralization and gender – RESX has no native support, so developers must create multiple keys manually (e.g., UserCount_One, UserCount_Many), which becomes messy in languages with complex grammar rules.
• Rigid fallback behavior – .NET falls back directly to the base Resources.resx if a localized file isn’t found. More advanced fallback paths (e.g., fr-CA → fr-FR → en) aren’t supported out of the box.
• Embedded non-string resources – RESX can contain binary assets like images or icons. This inflates file size, complicates version control, and isn’t practical in modern localization pipelines.
• Limited interoperability – RESX is tightly bound to the .NET ecosystem. Reusing translations in mobile apps, websites, or third-party tools requires extra conversion steps.
• Case sensitivity and key management issues – keys are case-sensitive and must be unique. Small differences (LabelText vs. labelText) can cause runtime errors or missing translations.

Teams may also run into the following workflow challenges when working with RESX files manually:

• Manual editing is error-prone – each RESX file stores translations as key–value pairs in XML. If you copy/paste strings manually into multiple RESX files, typos and inconsistencies easily creep in.
• Scaling to multiple languages gets messy – adding 2+ languages means managing 2+ separate files. Keeping them in sync with source language changes becomes a real challenge.
• No built-in collaboration – RESX is developer-centric. Translators or reviewers need technical skills or external tools like Visual Studio extensions just to work with the files.
• Lack of translation memory or automation – RESX doesn’t remember previously translated phrases. If the same string appears in multiple projects, you must translate it each time.
• Version control difficulties – RESX files can be large, and XML diffs are hard to review in Git. Collaboration through pull requests can quickly become unmanageable.

With Localazy, these challenges are minimized. You only need to upload your base RESX file, and the platform handles language variants, synchronization, and automation. Translators work in a user-friendly interface without touching XML, while developers benefit from Localazy CLI and API automation, translation memory, AI assistance, and clean version control. Built-in reviews and professional translation services ensure consistency and accuracy, making RESX files part of a scalable, collaborative localization workflow.

RESX (Resource XML) files are XML-based resource files used in .NET applications to store localized strings, images, and other assets. Each entry in a RESX file is a <data> element containing a name attribute (the key) and a <value> child node (the resource) — for example:

<?xml version="1.0" encoding="utf-8"?>
<root>
  <resheader name="resmimetype">
    <value>text/microsoft-resx</value>
  </resheader>
  <resheader name="version">
    <value>2.0</value>
  </resheader>
  <resheader name="reader">
    <value>System.Resources.ResXResourceReader, System.Windows.Forms</value>
  </resheader>
  <resheader name="writer">
    <value>System.Resources.ResXResourceWriter, System.Windows.Forms</value>
  </resheader>

  <data name="WelcomeMessage" xml:space="preserve">
    <value>Welcome to our app</value>
  </data>
  <data name="LogoutButton" xml:space="preserve">
    <value>Log Out</value>
  </data>
  <data name="ItemsInCart" xml:space="preserve">
    <value>You have {0} items in your cart.</value>
  </data>
</root>

Developers can also work with RESX programmatically using the .NET System.Resources APIs. For instance, using ResXResourceWriter to generate a .resx file:

using (var resx = new ResXResourceWriter("Resources.resx"))
{
    resx.AddResource("Greeting", "Hello");
    resx.AddResource("Farewell", "Goodbye");
}

And to read from a RESX file:

using (var reader = new ResXResourceReader("Resources.resx"))
{
    foreach (System.Collections.DictionaryEntry entry in reader)
    {
        Console.WriteLine($"{entry.Key}: {entry.Value}");
    }
}

In development, RESX files let you separate UI content from code, so you can support multiple languages without rewriting your application. For each target language, you create a separate RESX file (for example, Resources.en.resx, Resources.de.resx, etc.), and the .NET runtime automatically loads the right file based on the user’s culture settings.

For translation, this means you can hand off the language-specific RESX files to translators, who only need to work with the values while developers keep the structure and keys intact.

Pluralization refers to how words change based on quantity (e.g., 1 file vs. 2 files). With RESX files, this can be tricky because the format itself doesn’t natively support complex pluralization rules. Developers often work around this by creating multiple keys for each plural form (e.g., File_Singular and File_Plural) and then handling the logic in the application code.

Different languages follow very different pluralization rules—some have two forms, others have three or even more. Managing all these variations manually can quickly become a challenge.

Localazy helps by automatically accommodating these differences and applying the right rules for each language, so your text displays correctly across all markets. This is especially important for dynamic content like product quantities, time units, and notifications. Localazy also extracts context from preceding XML comments and sub-elements such as description, context, comment, and developer_comment, showing this information to translators to improve translation quality.When it comes to plural handling, Localazy offers several advanced options: Suffixed with camelCase - can be enabled by adding plural_postfix_cc to features in the upload section.

When it comes to plural handling, Localazy offers several advanced options:

• Suffixed with camelCase - can be enabled by adding plural_postfix_cc to features in the upload section.

<root>
  
  <data name="usersOne">
    <value>There is one user.</value>
  </data>
 
  <data name="usersOther">
    <value>There are $number users.</value>
  </data>
 
</root>

• Suffixed with brackets - can be enabled by adding plural_postfix_br to features in the upload section.

<root>
  
  <data name="users[one]">
    <value>There is one user.</value>
  </data>
 
  <data name="users[other]">
    <value>There are $number users.</value>
  </data>
 
</root>

• Defined using ICU - can be enabled by adding plural_icu to features in the upload section.

<root> 
  <data name="users">
    <value>There are {COUNT, plural, one {one user} other {# users}}.</value>
  </data>
</root>

Only one ICU plural can be used per string (otherwise conversion to Localazy’s plural structure isn’t possible). If more than two ICU plurals are included, the string remains in its original form.

Supported plural types are: zero (=0), one (=1), two (=2), few, many, other. Other ICU types like gender or number can still be used but won’t be converted—they’ll be preserved as-is in the string.

Read more about how to effectively deal with plurals in Localazy.

RESX files are XML-based, and when multiple team members edit them at the same time, it’s easy to run into merge conflicts—especially if translators, developers, or content managers all contribute in parallel. Even small changes like reordering or formatting can trigger conflicts in Git or other version control systems.

A common way to reduce these issues is to use branching: maintaining separate branches for different tasks or teams. Each branch keeps changes isolated until they are ready to be merged, which makes versioned development more manageable. This approach is particularly helpful for larger teams where multiple people need to update resources at the same time.

With Localazy, you can avoid most of these headaches altogether, since it acts as one source of truth, automates synchronization, and lets contributors collaborate without manually editing raw RESX files.

Read more about how to easily maintain and merge multiple projects in Localazy.

When working with RESX files, it’s common to have the same strings appear across different apps or projects—for example, shared UI elements, error messages, or onboarding flows. Without proper synchronization, you may end up duplicating work, introducing inconsistencies, or struggling to keep terminology aligned.

With Localazy, you can solve this using connected projects, which let you share translations from the translation memory across multiple projects. This way, duplicate terms are automatically reused, keeping terminology consistent and saving time.

Additionally, the duplicity linking feature allows you to link keys across projects. When the same content is updated in one place, it’s automatically reflected everywhere it’s linked—even across several projects—helping you maintain full control over duplicate strings in all languages.

Find further information on connected projects and duplicity linking in the Localazy documentation.

RESX files are XML-based, which makes them great for developers but tricky for translators without technical skills. Non-technical users may find it difficult to navigate the file structure, as each translation is wrapped in XML tags and metadata.

There are a few ways to handle this:

• Use a text editor to manually translate values. This requires working directly with XML.
• Convert the RESX file into a simpler format like CSV, though this adds an extra step.
• Use a translation management system (TMS) or dedicated RESX editor, which hides the XML and presents the strings in a clean, translator-friendly interface.

With Localazy, translating a RESX file is as simple as working with any other format. Just create a project, upload your file, add target languages, and start translating. To speed things up, you can even pre-translate the entire file in bulk using machine translation before handing it off for review.

When using RESX files, the recommended structure is a base file (e.g., Resources.resx) and then creating localized versions for each language or region (e.g., Resources.en-US.resx, Resources.fr-FR.resx) to keep things organized and ensure your app can load the right translations.

At runtime, the application automatically selects the file that matches the user’s locale. If no match is found, it falls back to the base file. This setup keeps translations consistent and predictable across projects.

With Localazy CLI, you don’t need to manually maintain all these files. You can upload your base RESX file, add target languages in the platform, and Localazy will handle the generation and synchronization of localized RESX files for you, making the whole process easier and less error-prone.

RESX files are powerful but can cause common localization errors, like incorrect plural forms, broken placeholders, or missing fallback values, if managed manually. These mistakes often happen when translators or developers have to work directly with the XML structure.

With Localazy, these challenges are handled automatically. Plural rules for each language are built-in, placeholders are protected so they won’t get accidentally changed, and fallback values are consistently maintained. This ensures your RESX files remain accurate and your app behaves as expected across all languages without adding extra manual work.