How to Batch Translate Multiple Files with AI

When you're launching your app in five new languages, you're not just translating one file — you're translating dozens of them, across multiple formats, and you need it done before the release date. Manual translation or key-by-key AI translation is too slow. Batch translation changes the math entirely.

What Batch Translation Means

Batch translation means processing multiple translation files — or multiple target languages — in a single operation. Instead of opening each file, translating it, and saving it manually, you upload all your files at once, select your target languages, and let the AI process everything together.

For a typical app with 200 translation keys targeting 10 languages, the difference is:

• Manual, key by key: 2,000 individual translations, hours of work, inconsistent terminology.
• AI batch translation: Upload files, select languages, wait a few minutes, download results.

Which File Formats Are Supported

A good batch translation tool handles the formats your project actually uses, not just the most common one:

• JSON — The standard for Vue (vue-i18n), React (react-intl), Angular, and Next.js (next-i18next).
• YAML — Common in Ruby on Rails and some Vue setups.
• ARB — Flutter's Application Resource Bundle format.
• iOS .strings — Apple's native localization format.
• Java .properties — Used in Spring and other Java applications.

The key requirement: the translation must preserve the file format, the key structure, and any placeholder variables like {name}, %s, or . A translator — human or AI — that changes the key names or garbles the placeholders produces output that breaks at runtime.

Translating Into Multiple Languages at Once

Batch translation should let you select multiple target languages in a single pass. You upload your English source file, tick the checkboxes for Spanish, French, German, Japanese, and Korean, and get back five correctly formatted output files. No repeating the process five times.

This is especially valuable when adding a new language to an existing product. You have 400 keys and need a complete French locale — running batch translation gives you a draft to hand to a human reviewer, rather than starting from scratch.

Why Terminology Consistency Matters in Batch Translation

AI translation at scale can produce inconsistent terminology if the same concept appears in different keys. "Submit" might become "Envoyer" in one key and "Soumettre" in another, confusing users and making your product feel unpolished.

The solution is a glossary — a list of terms that should always be translated the same way. A good batch translation tool lets you specify a glossary before running the translation, ensuring that "Submit" is always "Envoyer" across your entire French locale.

Batch Translate Your Files — With Glossary Support

Glot's Batch Translate lets you upload multiple translation files at once, select multiple target languages, optionally attach a glossary for consistent terminology, preview the cost before confirming, and download all results as a ZIP. It supports JSON, YAML, ARB, .strings, and .properties.

Each file is translated file by file with progress feedback. Results are available for preview, copy, or individual download before you even close the ZIP.

Batch AI translation isn't a replacement for human translators, but it's the fastest way to get a high-quality first draft that a professional can review. For many teams, the AI output is good enough for most keys, with human review focused on the UI copy that users see most.