An open-source L10n alternative to Crowdin (TMS)

Table of contents

Translation Management System

A Translation Management System (TMS) is a software platform designed to automate and streamline the translation and localisation (L10n) process. Traditionally, a TMS serves as a centralised hub where content is uploaded, organised, and assigned to human translators. It manages workflows, stores translation memories (to avoid re-translating the same sentence twice), and handles the delivery of translated files back to the developers or content managers.

In essence, a TMS has long served as the bridge between the technical code (where strings reside) and the human linguists (who understand the culture).

Crowdin

Crowdin is a veteran in this space. Founded in 2009, it emerged during a time when the primary challenge of localisation was connectivity. Its mission was clear: to place copywriters, translators, and project owners in relation to one another effectively.

For over a decade, Crowdin has been the industry standard for managing localisation. It solved the fragmentation problem by allowing teams to upload .po, .xml, or .yaml files and having translators work on them via a cloud interface. It built its reputation on solid workflow automation, allowing companies to scale from one language to ten without drowning in spreadsheets.

Intlayer

Intlayer is known primarily as an i18n solution, but it also integrates a CMS. Unlike Crowdin, which is limited to acting as a wrapper around your existing i18n setup, Intlayer controls the entire stack—from the bundling layer to remote content delivery—resulting in a smoother and more efficient content flow.

Why have the paradigms changed since AI?

While Crowdin optimised the human workflow, the arrival of Large Language Models (LLMs) has fundamentally shifted the paradigms of localisation. The role of the copywriter is no longer to create translations from scratch, but to review AI-generated content.

Why? Because AI is 1,000x cheaper and infinitely faster.

However, there is a limitation. Copywriting is not just about translation; it is about adapting the message to different cultures and contexts. We do not sell an iPhone to your grandmother in the same way we sell one to a Chinese business executive. The tone, the idiom, and the cultural markers must differ.

Today, the most efficient workflow is to translate and position your pages globally using AI first. Then, in a second phase, you use human copywriters to optimise specific high-traffic content to boost conversion once the product is already generating revenue.

Although Crowdin's revenue—driven mainly by its well‑proven legacy solutions—continues to perform well, I believe the traditional localisation sector will be severely impacted within a 5‑ to 10‑year horizon. The model of paying per word or per seat for a management tool is becoming obsolete.

Why is Intlayer a good alternative to Crowdin?

Intlayer is a solution born in the AI era. It was architected with the principle that in 2026, raw translation no longer holds intrinsic value. It is a commodity.

Therefore, Intlayer does not position itself merely as a TMS, but as a Content Management solution that deeply integrates a visual editor and internationalisation logic.

With Intlayer, you generate your translations at the cost of your inferences. You are not locked into a platform's pricing model; you choose the provider (OpenAI, Anthropic, Mistral, etc.), you choose the model, and you translate via CI (Continuous Integration), CLI, or directly via the integrated CMS. It shifts the value from access to translators towards management of context.

Comparison side-by-side

Intlayer offers a complete, all-in-one i18n solution that allows for a deep integration of your content. Your remote content can be synchronised directly with your codebase or your live application. By contrast, Crowdin often necessitates a rebuild of your application in your CI/CD pipeline to update content, creating friction between the translation team and the deployment process.

Furthermore, Intlayer can be utilised as a Feature Flag or A/B testing tool, enabling you to test different content variations dynamically — something standard TMS tools like Crowdin do not natively support.

Crowdin supports a wide range of file formats—including legacy types like .po, .xml, and .yaml, which can be beneficial for projects with established workflows or older systems. Intlayer, by contrast, works primarily with modern web-oriented formats such as .json, .js, and .ts. This means Intlayer may not be compatible with all legacy file formats, which is a consideration for teams migrating from older platforms.

Finally, for those prioritising data sovereignty and control, Intlayer is open-source and can be self-hosted. Docker files are available directly in the repository, giving you full ownership of your localisation infrastructure.