i18n JSON Translation Tool

i18n JSON Translation Tool is an AI-powered browser-based utility that translates JSON language files into over 30 languages, preserving the original JSON structure and formatting. It operates entirely within the user's browser, using API keys from providers like DeepSeek, Google, Anthropic, and OpenAI to perform translations without uploading data to any server.

What is i18n JSON Translation Tool?

i18n JSON Translation Tool is a web application that takes a JSON file (up to 10 MB) and a target language, and produces a translated JSON file with the same keys and structure. It runs exclusively client-side, meaning no data leaves the user's machine except API calls directly to the chosen AI provider. The tool is developed and maintained by an independent team (site: jsontrans.fun) and has been featured on Product Hunt, Startup Fame, Fazier, Twelve Tools, Turbo0, and AI Hunt List.

Key Features

• Code Friendly — Automatically formats translated JSON with proper indentation; supports copy and direct download of the result. Learn More
• Multi-language Support — Translates to and from over 30 languages, including English, Simplified Chinese, Traditional Chinese, Japanese, Korean, French, German, Spanish, Russian, and more. Learn More
• AI-Powered — Leverages AI models from DeepSeek, Google, Anthropic, and OpenAI to ensure translation accuracy and fluency. Learn More
• Data Security — All processing happens in the browser; the files and API keys are never sent to the tool's servers, only directly to the AI provider's API endpoint. Learn More
• File Size Support — Accepts JSON files up to 10 MB, with real-time preview of the original and translated content.
• AI Provider Selection — Users can choose among supported AI providers (DeepSeek, Google Gemini, Anthropic Claude, OpenAI) and enter their own API key for each translation session.

Who is it for?

• Frontend developers needing to internationalize web apps with JSON-based i18n files (e.g., using i18next, react-i18next, vue-i18n) who want to quickly generate translations for multiple languages without manual effort.
• Localization teams managing JSON translation files for mobile or web applications who require a fast, automated tool that preserves JSON structure and allows custom API keys for data privacy.
• Indie developers and small studios with limited budgets who need a free, no-registration tool to translate their app's language files without uploading sensitive data to third-party services.

What can you do with i18n JSON Translation Tool?

• Translate a React i18n JSON file: Upload your en.json, select Japanese, enter your DeepSeek API key, and get a structurally identical ja.json with translated values, ready to drop into your project.
• Batch translate for multi-language apps: Sequentially translate the same base file into 10+ languages by repeating the process, maintaining consistent terminology across all languages.
• Verify translations with real-time preview: Before finalizing, compare original and translated JSON side by side in the browser, ensuring keys are unchanged and values are properly localized.

How does it work?

1. Upload a JSON file (drag-and-drop or click; file size under 10 MB).
2. Select a target language from the dropdown (over 30 options, with a 'Show More Languages' button).
3. Choose your AI provider (DeepSeek is default) and enter your API key (stored temporarily in the browser session).
4. Click 'Start Translation' — the tool sends the JSON content to your chosen AI provider's API for translation.
5. Download or copy the resulting translated JSON file, which retains the original key names and structure.

FAQ

What does this tool do?

It translates JSON language files (like those used for i18n in web apps) into multiple languages while keeping the exact same keys and nesting structure. The translation is performed by AI models from DeepSeek, Google, Anthropic, or OpenAI, depending on your choice.

How secure is this tool? Will my data be uploaded?

All operations are performed locally in your browser. Your JSON file and API key are never sent to jsontrans.fun servers. The only external data transmission is your file content sent directly from your browser to the AI provider's official API endpoint (e.g., api.deepseek.com). After you close the tab, everything is cleared.

What languages are supported?

Over 30 languages are supported, including English, Russian, Spanish, German, Turkish, French, Japanese, Portuguese, Simplified Chinese, Traditional Chinese, Italian, Arabic, Polish, Greek, Dutch, Indonesian, Korean, Thai, and more. The full list is visible in the language dropdown on the site.

Is there a file size limit?

Yes, the maximum file size is 10 MB. For larger files, the tool recommends translating them in batches.

How to ensure translation quality?

Using AI models from reputable providers (DeepSeek, Google, Anthropic, OpenAI) helps ensure accuracy. The tool also supports custom dictionaries (mentioned in the FAQ on the site) to maintain consistency for specific terms, though this feature is not detailed in the current interface.