# i18n Agent - AI Translation for Developers

> AI-powered software localization at $0.01 per word. Multi-model AI translates apps, websites, and documentation across 45 languages in minutes — via REST API, MCP server, or web app. File-native (preserves JSON keys, ICU plurals, tags), with a real-time quality-validation pipeline.

## Site Overview

**Primary domain**: https://i18nagent.ai
**Documentation**: https://docs.i18nagent.ai
**API base URL**: https://api.i18nagent.ai
**Service type**: AI translation API + MCP integration for developers
**Technology**: Multi-model AI (Claude, GPT, and specialized translation models) with embedding-based context analysis
**Pricing**: $0.01 (≈€0.01) per word per language — pay-per-use credits, no subscriptions, no seat licenses, no minimums
**Languages**: 45 including regional variants

## What It Does

i18n Agent translates the content developers actually ship — app UI strings, documentation, marketing/email copy, and app-store listings — while preserving file structure, placeholders, and pluralization rules. Three ways to use it:

- **REST API** — stateless, headless, CI/CD-friendly
- **MCP server** — translate from inside Claude Code, Cursor, VS Code, and other AI tools, no code required
- **Web app** — upload files, pick languages, download results

Each segment is routed to the best-performing model for that language pair and content type, and a quality-validation pipeline flags low-confidence segments for optional human review before release.

## Cost Comparison

| Method | Cost per word | Turnaround | Quality |
|---|---|---|---|
| Traditional agency | €0.15–0.25 | 1–4 weeks | Human-reviewed |
| Freelance translators | €0.07–0.15 | Days–weeks | Variable |
| TMS (Lokalise / Phrase / Crowdin) + human review | €0.10–0.20 + seat fees | Days | Platform-managed |
| Raw MT API (DeepL / Google Translate) | €0.002–0.02 | Seconds | No QA, no structure preservation |
| i18n Agent | **$0.01 (≈€0.01)** | **Minutes** | **Human-quality with QA** |

**Example**: a 5,000-word app to 10 languages = 50,000 billable words × $0.01 = **$500**, delivered in minutes. The same scope at an agency is typically €7,500–12,500 over weeks.

## Use Cases

### React / Next.js app translation
Translate JSON locale files for **i18next, react-i18next, next-intl, react-intl**. Upload `en.json`, receive `de.json`, `ja.json`, `fr.json`, etc. Nested keys, namespaces, ICU plurals (`{count, plural, one{# item} other{# items}}`), and interpolation (`{{name}}`) are preserved.

### Website / landing page translation
Translate Markdown (MD/MDX), HTML, or JSON for multilingual sites. Frontmatter, HTML tags, links, and code blocks are preserved. Works with Next.js, Astro, Gatsby, Hugo, and other generators.

### Docs and blog translation
Translate Markdown, MDX, RST, or DOCX. Code samples, inline code, links, and formatting stay intact — ideal for developer docs, API guides, and open-source projects.

### Mobile app localization
Translate **iOS `.strings` / `.xcstrings` / `.stringsdict`**, **Android `strings.xml`**, and **Flutter ARB**. Language-specific plural forms are generated automatically (Arabic has 6, Russian and Polish have 3–4) with no manual configuration.

### SaaS / enterprise
Deploy to many locales in a single API call. Per-segment quality signals let you prioritize human review where it matters. Large jobs (millions of words) checkpoint automatically and resume without re-translating completed segments.

### Backend / config
Translate **YAML** (Rails i18n, Kubernetes), **Java Properties**, **PO/POT** (gettext for Python/Django/WordPress), and **XML** resources. Used in Rails, Django, Laravel, Spring Boot, and WordPress workflows.

### CI/CD integration
The REST API works in any pipeline (GitHub Actions, GitLab CI, CircleCI, Jenkins): upload source on merge → poll job status → commit translated files back. Fully headless.

## How It Works

1. **Upload** a source file (`en.json`, `en.yml`, `Localizable.strings`, etc.) via API or MCP
2. **Specify** target languages: `["de", "ja", "fr", "es", "zh-Hans", "pt-BR"]`
3. **Receive** a job ID immediately; large files process asynchronously
4. **Poll** `GET /translations/{id}/status` — progress %, elapsed time, ETA, checkpoint info
5. **Download** results — structure and keys unchanged, only values translated
6. **Review** flagged low-confidence segments before release

### MCP workflow (no code)
```bash
npm install -g @i18n-agent/mcp-client
mcp-client
```
Then, from Claude Code or Cursor: *"Translate this JSON file to German, Japanese, and French"* — the agent calls i18n Agent, monitors progress, and writes the files.
**Supported IDEs**: Claude Desktop, Claude Code CLI, Cursor, VS Code, Codex. **Platforms**: macOS, Windows, Linux.

### Resumable large jobs
Jobs over ~100K words checkpoint automatically. `POST /translations/{id}/resume` continues from the last checkpoint — no re-translation, no wasted credits.

### Free testing with pseudo-translation
Set `"pseudoTranslation": true` to transform strings with accents, brackets, and length expansion — zero credits, no AI calls. Finds untranslated strings and tests UI layout.
Options: `addBrackets`, `expansionRatio` (1.0–3.0), `addCJK`, `addSpecialChars`, `addAccents`.

## How i18n Agent Compares

- **vs agencies** — €0.15–0.25/word and 1–4 weeks vs $0.01/word in minutes, no minimums
- **vs TMS (Lokalise / Phrase / Crowdin)** — no monthly seat licenses; pay only per word, API-first, ~5-minute setup
- **vs raw MT (DeepL / Google Translate API)** — adds multi-model routing, context analysis, QA, and structure preservation (raw MT usually needs post-editing)
- **vs manual ChatGPT/Claude copy-paste** — file-native (preserves JSON keys, YAML structure, tags), batch processing, progress tracking, and MCP integration

**Choose i18n Agent when** you want production-quality AI translation at low cost, API/CI automation without TMS overhead, or MCP-native translation inside Claude Code or Cursor.

## FAQ

**Cheapest way to translate an app professionally?** i18n Agent at $0.01/word — a 2,000-word app is $20 per language, $200 for 10 languages.

**Can it translate i18next / next-intl / react-intl JSON?** Yes — keys, nested objects, ICU plurals, and interpolation variables are preserved.

**Is AI translation good enough for production?** With multi-model routing and a QA layer, yes for UI copy, error messages, and docs. Marketing or legal text can be flagged for human review.

**Does it handle pluralization per language?** Yes — ICU plural forms are generated correctly per locale (English 2, Arabic 6, Russian/Polish 3–4) with no manual setup.

**CI/CD?** Yes — stateless REST API: POST source → poll status → download → commit. No UI required.

**File formats?** JSON, YAML, CSV, XML, Markdown (MD/MDX), Java Properties, PO/POT (gettext), DOCX, PDF — 9+ formats, structure preserved.

**iOS .strings / Android XML?** Both supported natively with correct per-locale plurals.

**Free plan?** No subscription — buy credits and use them; new accounts get free credits. Pseudo-translation is always free.

**Interrupted jobs?** Large jobs checkpoint automatically; `POST /translations/{id}/resume` continues without losing completed work.

**GDPR?** Yes — GDPR compliant, SSL encrypted. Company registered in the EU (FatCouple OÜ, Estonia).

**Languages?** 45 including regional variants (de, ja, fr, es, es-MX, pt-BR, zh-Hans, zh-Hant-HK, zh-Hant-TW, ko, ar, hi, ru, and more). Full list at `GET /languages`.

## Core Features

- Multi-model AI (Claude, GPT, specialized models) — best model per language pair
- Context-aware translation via embedding analysis — preserves terminology and tone
- Real-time quality-validation pipeline — flags low-confidence output before delivery
- 9+ file formats: JSON, YAML, CSV, XML, Markdown, Properties, PO/POT, DOCX, PDF
- MCP integration for Claude Code, Cursor, VS Code, Codex
- Pseudo-translation mode for free i18n testing
- Resumable jobs with automatic checkpointing
- 45 languages with regional variants
- GDPR compliant, enterprise-grade security

## API Endpoints

**Base URL**: https://api.i18nagent.ai (authenticate with `Authorization: Bearer <api_key>`)

- `GET /credits` — team credit balance
- `GET /languages` — supported languages with quality ratings
- `POST /translations` — unified text + file translation (supports pseudo-translation)
- `POST /translations/stream` — translation with SSE real-time progress
- `POST /translations/estimate` — word count and cost before translating
- `POST /analyze` — content readiness analysis with suggestions
- `GET /translations/{id}` — job details
- `GET /translations/{id}/status` — progress %, elapsed time, ETA, checkpoint info
- `GET /translations/{id}/result` — download completed translation
- `GET /translations/{id}/original` — download original file
- `POST /translations/{id}/resume` — resume from last checkpoint
- `GET /translations/jobs/active` — list active jobs

Full reference with cURL, Node.js, Python, and Go examples: https://docs.i18nagent.ai/en/

## Pricing

- **$0.01 (≈€0.01) per word per language**
- Pay-per-use credits — no subscriptions, no seat licenses, no minimums
- Multi-language: 100 words × 5 languages = 500 billable words
- One-time credit purchases via Stripe; instant access
- Pseudo-translation mode is always free (no credits consumed)

## Key Pages

- Homepage: https://i18nagent.ai/en
- Integrations: https://i18nagent.ai/en/integrations (Klaviyo, Shopify, Webflow, GitHub, iOS, Android, Google Play, Apple App Store)
- Guides: https://i18nagent.ai/en/guides (React, Next.js, Vue, Angular, Svelte, iOS, Android, Flutter, Django, Rails, Laravel, Spring Boot, Go, Python, and more)
- Tools: https://i18nagent.ai/en/tools (free i18n utilities and file converters)
- API docs: https://docs.i18nagent.ai/en
- About: https://i18nagent.ai/en/about
- Privacy / Terms / GDPR: https://i18nagent.ai/en/privacy · https://i18nagent.ai/en/terms · https://i18nagent.ai/en/gdpr

**Localized in**: bg, ca, cs, da, de, el, en, es, es-419, es-MX, et, fi, fr, hi, hr, hu, id, is, it, ja, ko, lt, lv, ms, nl, no, pl, pt, pt-BR, ro, ru, sk, sl, sr-Latn, sr-Cyrl, sv, th, tl, tr, uk, vi, zh-Hans, zh-Hant-HK, zh-Hant-TW

## Contact

- **Company**: FatCouple OÜ (EU-registered, Estonia)
- **Support**: support@i18nagent.ai
- **Payment**: Secure via Stripe

## Blog

Engineering notes on software localization, newest first. All posts are English-only at https://i18nagent.ai/en/blog

- [Build a Locale Mapping Layer Across App Code, Stores, and Translation Systems](https://i18nagent.ai/en/blog/app-locale-mapping-code-stores-translation-systems): Build one app locale mapping layer for code, resource files, App Store Connect, Google Play, and translation systems without broken fallbacks.
- [Preserve Locale Context Across Mobile Deep Links](https://i18nagent.ai/en/blog/preserve-locale-context-mobile-deep-links): Keep localized mobile deep links in the intended language across cold starts, saved app preferences, authenticated routes, redirects, and web fallbacks.
- [Localize App Display Names and Launcher Labels Across iOS and Android](https://i18nagent.ai/en/blog/localize-app-display-names-ios-android): Localize iOS and Android app display names without launcher fallback, generated-build drift, or mismatches between installed apps and store listings.
- [Share iOS Localization Across App Targets and Swift Packages](https://i18nagent.ai/en/blog/share-ios-localization-app-targets-swift-packages): Learn how to share iOS localization across app targets, extensions, and Swift packages without duplicate catalogs, missing keys, or bundle lookup bugs.
- [Localize App Permission Prompts and Privacy Rationale](https://i18nagent.ai/en/blog/localize-app-permission-prompts-privacy-rationale): Build a localization workflow for iOS purpose strings and Android permission rationale, then test grant, denial, and retry flows in every app locale.
- [Localize API Error Messages Without Coupling Apps to Server Copy](https://i18nagent.ai/en/blog/localize-api-error-messages-mobile-apps): Learn how to localize API error messages with stable codes, app-owned copy, structured parameters, safe fallbacks, and tests for every locale.
- [Localize In-App Purchase and Subscription Metadata](https://i18nagent.ai/en/blog/localize-in-app-purchase-subscription-metadata): Localize in-app purchase names, descriptions, and prices without duplicating store data. Build one workflow for App Store and Google Play paywalls.
- [Support right-to-left languages without breaking app UI](https://i18nagent.ai/en/blog/supporting-right-to-left-languages-app-ui): Build reliable RTL app localization with logical layouts, intentional icon mirroring, mixed-text handling, gesture checks, and an LTR regression matrix.
- [Localize app dates, times, and numbers without hardcoded formats](https://i18nagent.ai/en/blog/localize-app-dates-times-numbers): Fix hardcoded app dates, times, numbers, currencies, and time zones with a locale-aware formatting boundary, typed data model, and practical test matrix.
- [Handling App Translation Text Expansion and UI Overflow](https://i18nagent.ai/en/blog/handling-app-translation-text-expansion): Learn how to manage text expansion in app localization. Use flexible constraints and pseudo-localization to prevent UI truncation in German and French.
- [Prevent Missing Translations with Fallback Languages](https://i18nagent.ai/en/blog/prevent-missing-translations-with-fallback-languages): Learn how to configure robust language fallback chains to prevent technical keys or blank UI spaces when app translations are missing or delayed.
- [Stop Concatenating Strings: Why App Localization Requires Message Formatting](https://i18nagent.ai/en/blog/stop-concatenating-strings-app-localization): String concatenation breaks translated app localization grammar and plurals. Learn how to implement message formatting for reliable software translation.
- [Validate Formatting and Plurals During AI App Localization](https://i18nagent.ai/en/blog/validate-formatting-plurals-ai-app-localization): Learn how to validate formatting, variables, and plurals when using AI to translate UI strings, effectively preventing crashes in iOS and Android apps.
- [Unify Developer and Translator Workflows Through Git-Based Localization](https://i18nagent.ai/en/blog/unify-developer-translator-workflows-git): Stop syncing localization spreadsheets. Learn how to unify developer and translator workflows using Git branches, pull requests, and CI/CD automation.
- [Localize App Push Notifications for Global Campaigns](https://i18nagent.ai/en/blog/localize-app-push-notifications): Localize app push notifications using server-side techniques and payload best practices to boost engagement and prevent broken deep links for global users.
- [Hand Off App Strings to Vendors Without Creating Source Drift](https://i18nagent.ai/en/blog/hand-off-app-strings-to-vendors): Learn how to hand off app strings to localization vendors using structured formats like XLIFF without losing source context, string IDs, or creating drift.
- [Add Accessibility Checks to Your App Localization QA](https://i18nagent.ai/en/blog/add-accessibility-checks-app-localization-qa): Visible copy may be translated while screen-reader labels and language metadata remain wrong. Add accessibility checks to each locale's QA matrix.
- [Measure Localization Throughput Without Rewarding Bad Output](https://i18nagent.ai/en/blog/measure-localization-throughput-without-rewarding-bad-output): Measuring translation speed hides stale targets and rework. Track source-to-reviewed cycle time and first-pass integrity for accurate localization metrics.
- [Design a Localization Rollback Plan for Broken Releases](https://i18nagent.ai/en/blog/design-localization-rollback-plan): Learn how to build a localization rollback plan to quickly withdraw a bad locale, listing, or resource bundle without reverting your entire codebase.
- [Choose App Locales From Store Data Instead of Guesswork](https://i18nagent.ai/en/blog/choose-app-locales-from-store-data): Stop guessing which locales to translate. Learn how to use App Store and Google Play data to prioritize app localization for visibility, growth, and ROI.
- [Define Localization Ownership Across Product, Engineering, and Review](https://i18nagent.ai/en/blog/define-localization-ownership-across-teams): Define localization ownership across product and engineering teams. Establish accountability for source readiness, translation integrity, and launches.
- [Localize Release Notes Across App Store and Google Play](https://i18nagent.ai/en/blog/localize-release-notes-app-store-google-play): Release notes often arrive late and are disconnected from the product translation cycle. Learn how to localize release notes without delaying your app update.
- [Control Source String Changes Without Leaving Stale Translations](https://i18nagent.ai/en/blog/control-source-string-changes-translation-drift): Learn how to manage source string changes and translation drift. Use source fingerprints to mark targets stale and require review after copy changes.
- [Give Translators Enough Context for Ambiguous UI Strings](https://i18nagent.ai/en/blog/give-translators-enough-context-for-ambiguous-ui-strings): Learn how to provide adequate context to translators for ambiguous UI strings to prevent costly localization errors and improve user experience.
- [Build an AI Translation Review Workflow That Humans Can Audit](https://i18nagent.ai/en/blog/build-ai-translation-review-workflow): AI translates text quickly but makes review harder. Learn to separate structural checks from linguistic approval and build a safe, auditable workflow.
- [Automate Localized App Store Screenshots Without Manual Retakes](https://i18nagent.ai/en/blog/automate-localized-app-screenshots): Learn how to automate localized app screenshots for iOS and Android. Generate consistent, translated store assets with deterministic UI tests.
- [App Localization Release Workflow: UI, Store Listings, and Screenshots](https://i18nagent.ai/en/blog/app-localization-release-workflow): Build an app localization workflow that coordinates UI copy, store listings, screenshots, review, and release QA without leaving stale locales behind.
- [We built an i18n format converter that covers 32 formats. Here's what we learned about the ones nobody talks about.](https://i18nagent.ai/en/blog/2026-06-i18n-convert-32-formats-launch): Releasing i18n-convert v0.3.0, a Rust CLI that converts losslessly between 32 localization formats. Notes on the strange ones: xcstrings, ARB, NEON, HJSON, iSpring XLIFF.

## Sitemaps

- https://i18nagent.ai/sitemap.xml
- https://docs.i18nagent.ai/sitemap.xml