Software localization: what it covers, how to choose a platform and why we recommend no agency

Software localization is the adaptation of a product, application or content to a specific target market, called a locale. The World Wide Web Consortium (W3C) defines localization in its internationalization guide as the “adaptation of a product, application or document content” to suit a market (W3C, Localization vs. Internationalization, read on 20 October 2026).

What does localization mean in software

In practice it means the interface and documentation read naturally for the user, and the product behaves as local users expect. W3C lists what it covers beyond translation:

• number, date and time formats, currency and keyboard layouts;
• sorting rules, symbols, icons and colours;
• removing references that could be misread or offensive in a culture;
• meeting local legal requirements, and address and phone number formats;
• script-specific readability needs, and sometimes rethinking business logic or visual design.

What is localization in software

Localization is one of three terms that are often mixed up:

W3C notes that internationalization does not require translating anything, and that retrofitting a product for localization later is harder and more expensive. That is why the first question to a provider is about your code, not your languages.

We cannot name one. Sortlist lists 584 providers for software localization; we read the reviews of the 45 with the most reviews, and none of them describes localization. None of the 220 organic profile descriptions mentions it either: the listing is made of mobile and web developers. Several of the best-reviewed ones are excellent at building software, but a review that praises a website does not tell you how they handle plural forms in Arabic.

Three kinds of provider actually do the work. Ask which one you are talking to:

If you need a translation specialist, Sortlist has dedicated listings: website localization, game localization and translation services.

No single platform is best: the right one depends on your repositories, design tools, languages and volume. Search results for this question repeat the same four names. Below is how each describes itself on its own site (read on 20 October 2026); these are vendor claims, not Sortlist assessments, and we have not tested them.

Selection guides repeat the same criteria: translation memory and terminology management, and integration with your workflow. Add these checks:

• Does it connect to your code repository and design tool without manual file exports?
• Can you export your translation memory and glossary in a standard format if you leave?
• Does it preview strings in context, in the running app?
• How does it handle right-to-left scripts and plural forms for your languages?
• How is machine translation used, and can you require human review before release?

Run a trial on one real feature with two or three platforms, on the same strings, and compare the review effort, not the demo.

1. 1

   Audit the code for internationalization

   Hard-coded text, concatenated sentences, fixed-width layouts, date and number formats. W3C stresses doing this early because retrofitting is harder and more expensive.

2. 2

   Choose the locales and the scope

   Languages and regions, plus what changes: UI strings, help, marketing pages, legal text, payments and support.

3. 3

   Extract the text and set up the tooling

   Connect the repository, create the glossary and translation memory, and agree who approves terms.

4. 4

   Translate and review

   Human review by native speakers of the target locale, with the context of screenshots or a running build.

5. 5

   Test in the product

   Check truncation, right-to-left layouts, plural forms, formats and legal text on real devices.

6. 6

   Release and keep going

   Add new strings to the same flow as features ship, so translations never lag behind the code.

Tip: send the same 50 real strings to each shortlisted provider and compare the questions they ask. Good localizers ask about context before they translate.

These providers appear on the first page of Sortlist’s software localization listing. They are mostly software and mobile app developers. We list them with their rating and number of reviews, not as recommendations for localization: ask each for localization references.

Sortlist lists 584 providers for software localization. We evaluated the 220 organic profiles on the first pages (sponsored placements are shown apart), read the reviews of the 45 with the most reviews and searched them and the profile descriptions for localization, internationalization and multilingual work. Our usual rule for a ranking is at least three verified reviews that describe the service; here the count is zero, so we publish no score.

• Definitions come from the W3C internationalization guide; platform descriptions are the vendors’ own, read on 20 October 2026.
• The providers listed above are shown unscored, as they appear on the first page of the listing.
• No agency can pay to appear in these lists; 6 sponsored agencies are shown in a separate, labelled block.

If localization specialists join Sortlist and collect reviews, this page will move to a ranking with the same weighted formula as our other pages.