What is TMS (Translation Management System)?

A translation management system is the central platform where localization work happens. It stores source strings and their translations, tracks what is missing or outdated per language, coordinates translators and reviewers, and syncs content back to the codebase or delivers it at runtime.

Without a TMS, teams typically pass language files around by email or pull request. That works for one developer and two languages, then breaks down: merge conflicts in lang files, no visibility into coverage, and translators forced to edit raw PHP or JSON. A TMS replaces that with a web editor, roles and permissions, and machine-readable state, and coverage dashboards come along for free.

TMS platforms differ mainly in how they connect to your stack. File-based systems import and export formats like PO or XLIFF. API-first systems, LangSyncer among them, sync keys directly with the application and can serve translations live, so publishing a fix does not require a deploy.