iOS App Localizer
Apple · Writing
iOS App Localizer is the String Catalogs system Apple added in Xcode 15, a built-in app localization tool that gathers every string, translation, and plural in one file so you can ship in 40+ languages.
About iOS App Localizer
What Is iOS App Localizer
iOS App Localizer is the name given to the String Catalogs workflow that Apple introduced in Xcode 15. It isn't a standalone app you download. It lives inside Xcode, the tool developers already use to build iPhone and iPad software. When you add a string catalog file to a project, the compiler scans your code on every build and pulls out the text a user can see, then drops each line into one editable list. Instead of chasing scattered .strings and .stringsdict files, you get a single source of truth for app translation.
The problem it solves is sprawl. Older projects kept one strings file per language, so a new button label meant edits in a dozen places, and there was no clear signal about which lines still lacked a translation. A string catalog flips that. One file holds the source language plus every target language, and Xcode shows a completion percentage per language, so gaps are visible at a glance. You can also mark translation state, handle plurals, and vary text by device without leaving the editor.
There are limits worth knowing. iOS App Localizer is Mac and Xcode only, so it's no help if you build on Windows or in a no-code tool. It also expects you to supply the translations. Xcode extracts and organizes strings, but it won't write the German for you unless you use the newer agent-assisted translation in recent Xcode versions. And migrating a large older project takes a deliberate pass, since you're moving every legacy strings file into the new format.
Getting Started
- Open your project in Xcode 15 or later and select the project file in the navigator.
- Under Info, find the Localizations section and click the plus button to add each language you want to support.
- Right-click your app folder, choose New File from Template, pick the String Catalog type, and name it Localizable so Xcode treats it as the default catalog.
- Build the project once. Xcode extracts localizable strings from your code and lists them in the catalog.
- Open the catalog, fill in each language column, and mark entries as translated. Xcode tracks the completion percentage as you go.
Product Information
A quick look at iOS App Localizer's pricing, supported platforms, and performance.
Best for
The users, tasks, and scenarios where this tool fits best.
Users
- Indie iOS developers shipping to a global audience
- Small teams without a dedicated localization engineer
- Developers migrating a legacy project
- Product managers who need visibility
Tasks
- Managing iOS internationalization across a whole codebase
- Tracking which strings still need a translation
- Handling plurals correctly
- Varying text by device
- Keeping source and translations in sync
- Exporting work for translators
Scenarios
- Adding a second language to an app that only shipped in English
- A release where marketing wants the app name localized too
- Onboarding a freelance translator
- Reviewing translation quality before launch
Key features
Automatic string extraction
Every time you build, Xcode scans your code and SwiftUI views for user-facing text and adds anything new to the catalog. You stop maintaining strings by hand and stop wondering whether a freshly added label made it into the translation set. For SwiftUI the extraction is largely automatic, which removes the old step of wrapping text in localization macros before it can be translated.
One file, every language
String Catalogs replace the old pattern of one strings file per language with a single .xcstrings file holding the source language and all targets. When you localize an iOS app this way, every target language sits in one file instead of a folder of separate ones. Reviewers can see all translations side by side, and a code review that touches text shows one clean diff instead of a dozen small ones.
Translation progress tracking
The editor shows a completion percentage for each language and flags entries that are extracted, translated, or still missing. That turns "are we ready to launch" into a number anyone on the team can read, rather than a guess about whether the strings files are current.
Plurals and device variations
You handle plural rules and device-specific variants inside the catalog. Rather than separate .stringsdict files per language, you add the plural forms next to the string, and you can show different text on iPhone, iPad, and Mac from the same entry, which keeps layout-sensitive copy manageable.
Import and export workflows
You export a localization catalog or XLIFF files, hand them to translators outside Xcode, and import the results back into the project. This fits teams that use an agency or freelancer and keeps their work aligned with the exact strings in the codebase.
InfoPlist support
A dedicated InfoPlist string catalog covers values that live in your property list, such as the app display name and permission prompts. Localizing those used to mean separate plist files per language, and the catalog folds them into the same workflow as the rest of your text.
Built into the Apple toolchain
String Catalogs run inside Xcode with no third-party library or service to add, and no extra dependency to keep updated. That keeps localization in the same place as your builds and signing, which lowers the chance that a language gets dropped between tools.
Pros and cons
Pros
- Single source of truth: one catalog holds source and every translation, so there's no hunting across per-language files.
- Automatic extraction: Xcode finds new user-facing strings on each build, which cuts the busywork of manual string tracking.
- Built-in progress view: per-language completion percentages make launch readiness a concrete number.
- No extra tooling: it ships inside Xcode, so there's no third-party service to sign up for or maintain.
- Solid plural and device support: plurals and device-specific variants live in the same file as the base string.
Cons
- Mac and Xcode only: there's no Windows or Linux path, so teams building cross-platform outside Apple's tools can't use it directly.
- It organizes translations, it doesn't write them: without the newer agent-assisted translation you still supply the target-language text yourself.
- Migration takes planning: moving a large legacy project with many .strings files into the new format is a deliberate task, not a one-click switch for everything.
- Tied to Apple's release cycle: format and feature changes arrive with new Xcode versions, so you can't adopt improvements independently.
Frequently asked questions
iOS App Localizer is the String Catalogs system in Xcode 15 and later. It extracts the text a user sees from your code, stores the source strings and every translation in one .xcstrings file, and tracks how complete each language is.
Related content
Explore related tools, skills, and articles for iOS App Localizer.
iOS App Localizer Alternatives
Emailwritr
Emailwritr · Writing · MarketingEmailwritr is an AI email copywriting tool built for affiliates, course creators, and online businesses that want more revenue from the list they already own. Instead of blank pages or generic chatbot prompts, this AI email writer generates welcome sequences, launch campaigns, cart recovery emails, and promo series from frameworks modeled on well-known direct-response copywriters. You connect your autoresponder, answer a few questions about your offer, and it writes the copy for you.
Swms
Swms AI · Writing · Productivity · BusinessSwms is an AI safety compliance tool that turns a plain description of a job into ready-to-use safety documents. Describe your project, trade, and known hazards, and it writes a safe work method statement, job hazard analysis, safe work procedure, RAMS, or safety data sheet in seconds. It also ships with Oscar, a chat assistant that answers workplace safety questions in any language. Teams in construction, mining, transport, and warehousing use it to cut the paperwork that usually eats into a workday.
Prosp
Prosp · Writing · Voice & Language · MarketingProsp is an AI LinkedIn outreach tool built for agencies and sales teams, and it writes the message and the voice note in your own voice for each prospect so they actually reply. You connect your accounts, find leads, and let the AI draft and send personalized messages at scale, all from one inbox. It's built for people running outbound at volume. That's the whole pitch. Every touchpoint still has to feel human.