Key & Structure Preservation
Keys are never translated or modified. Every nested object, array, and value type stays exactly as in the original. Your JSON remains valid and production-ready.
Translate JSON Files Online - Keys, Values & Nesting Preserved
Upload any JSON file and get an accurate translation in 100+ languages. Keys, placeholders, arrays, and nested objects - all preserved. Production-ready output.
JSON workflow
Translation example
A localisation JSON file, English to Spanish
The first 34 lines of Home Assistant's Google Calendar strings (Apache-2.0). Keys, {placeholders} and [%key:…] references come back exactly; only the sentences change.
Source
Result
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Keys identical, nothing renamed
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Every placeholder survives in its own string
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Cross-file references are left exactly as they were
2026-10-08 verified — Amanda Lee
JSON features
Placeholder Protection
Variables like {name}, {{count}}, %s, and ICU patterns are detected and preserved.
Lightning-Fast Results
Most JSON files are translated in seconds. Cloud-based AI handles even large config files and deeply nested structures.
100+ Languages Supported
Translate JSON files between 100+ languages including Spanish, French, German, Arabic, Chinese, Japanese, and Korean.
Why ForgeFile Is the Best JSON Translator Online
Need to translate a JSON file without breaking your app's data structure? ForgeFile is an AI-powered JSON translator that converts your localization files into 100+ languages while preserving every key, placeholder, array, and nested object. Whether it's i18n strings, API responses, or config data, your translated JSON is valid, diff-friendly, and ready for production.
How ForgeFile Translates JSON Files
Our translation engine understands JSON semantics. When you translate a JSON file, ForgeFile:
- Parses the full object tree - keys, values, arrays, and nested structures
- Translates only string values using context-aware AI that understands UI text and app terminology
- Preserves keys, placeholders ({name}, {{count}}, %s), ICU patterns, and variable references
The result is a valid JSON file you can drop directly into your project - no broken syntax, no missing keys, no corrupted placeholders.
Placeholder-Safe & Developer-Friendly Output
ForgeFile is built for developer workflows:
- Keys are never translated or modified - only string values are localized
- Placeholders like {username}, {{count}}, %d, and $t() references are preserved
- ICU MessageFormat patterns (plurals, selects, numbers) stay valid
- Nested objects and arrays maintain their exact structure and depth
- Output is diff-friendly with consistent formatting for clean version control
Built for App Localization, APIs & SaaS Products
ForgeFile handles the JSON files development teams work with every day:
- i18n & App Localization - translate React, Vue, Angular, and Next.js localization files (i18next, react-intl, vue-i18n)
- Mobile Apps - localize Flutter, React Native, and Expo string bundles
- SaaS & Web Products - translate UI labels, error messages, notifications, and onboarding flows
- API & Config Data - localize API response templates, webhook payloads, and configuration values
Bulk translation and API access are available for CI/CD pipeline integration. All files are encrypted in transit and at rest - fully GDPR-compliant.
Why Developers Choose ForgeFile for JSON Translation
- Key-Safe Translation - keys are never modified, only string values are translated
- Placeholder Protection - {variables}, {{templates}}, and ICU patterns stay intact
- 100+ Languages - including right-to-left scripts (Arabic, Hebrew) and CJK characters
- Diff-Friendly Output - clean formatting for git diffs and code review
- No Software to Install - works entirely in your browser
The JSON format's grammar is defined in RFC 8259.
How to Translate a JSON File in 4 Steps
- 1
Upload Your JSON File
Drag and drop your . json file, or browse to select it. The maximum file size depends on your plan.
- 2
Select Source & Target Language
Choose from 100+ languages. ForgeFile auto-detects the source language and understands app UI context for natural translations.
- 3
Configure Translation Settings
Choose which keys to translate and which to skip. Select output formatting (minified or pretty-printed) for your workflow.
- 4
Download Your Translated JSON
Your translated JSON is ready in seconds. All keys, placeholders, and nesting are preserved - drop it into your project and deploy.
JSON Translation FAQ - Common Questions Answered
How do I translate a JSON file online?
Upload your JSON file to ForgeFile, select your target language, and click Translate. Our AI translates string values while preserving all keys, placeholders, and structure - typically in seconds.
Are JSON keys translated or modified?
No. ForgeFile translates only string values. Keys are never modified, renamed, or reordered. Your translation file maps 1:1 with the original.
Are placeholders and variables preserved?
Absolutely. ForgeFile detects and protects placeholders like {name}, {{count}}, %s, %d, $t() references, and ICU MessageFormat patterns.
Does it work with i18next, react-intl, or vue-i18n?
Yes. ForgeFile handles all major i18n JSON formats including i18next, react-intl, vue-i18n, Angular i18n, and custom localization structures.
Are nested objects and arrays preserved?
Yes. Every level of nesting, array order, and object structure is preserved exactly. The translated JSON has the same shape as the original.
Is there a file size limit?
For larger files or CI/CD pipeline integration, contact us about enterprise plans with API access. The maximum file size depends on your plan.
Is my JSON data secure during translation?
Files are encrypted in transit and at rest. How long they are kept depends on your plan.
What is the difference between translating JSON and XML localization files?
JSON uses key-value pairs and is standard for modern web and mobile apps. XML uses tags and attributes and is common for Android and legacy systems. ForgeFile handles both natively with full structure preservation.
Guides for this workflow
Ready to Translate Your JSON Files?
Upload your JSON file and get production-ready translated output in seconds. Keys, placeholders, and structure preserved, every time.