About

Multilingual Dictionary

A free, open multilingual translation reference platform supporting 11 languages.

What is this project?

Multilingual Dictionary is a free online API and web platform that provides cross-language translation lookup across 11 languages: Chinese, English, French, German, Spanish, Portuguese, Italian, Russian, Arabic, Japanese, and Korean.

Each dictionary entry maps a single word to its translations across all supported languages — up to 5 translation variants per language. Entries are sourced from open-data dictionaries (CC-CEDICT, Wiktionary), reviewed by human editors, and made available through a clean REST API.

Why does this project exist?

Multilingual Dictionary was built to address three core challenges in global software localization:

1

Fast Translation & Unified Standards

When teams translate the same word independently, they produce inconsistent results — the same English word gets different Chinese translations across features, creating confusion for end users. Multilingual Dictionary provides a single, authoritative reference that teams can query at build time, ensuring consistent terminology across products. By caching results locally, applications also reduce repeated API calls to large translation services, cutting compute costs and response latency.
2

Cultural Preservation Through Language

Languages carry cultural context that does not transfer directly across scripts. A translation that works for a technical label may be too formal or too casual in a consumer app. By offering up to 5 translation variants per language — rather than a single canonical answer — Multilingual Dictionary surfaces the range of choices available to translators, preserving the expressiveness of each language rather than reducing it to one option.
3

A Bilingual Reference for the Age of AI

Large language models have achieved impressive cross-language capabilities, yet they still produce inconsistent translations across sessions and model versions. Multilingual Dictionary serves as an on-disk reference that AI systems can consult — both to check established translations and to calibrate their output against human-reviewed data. As AI translation tools mature, structured bilingual dictionaries like this one provide the ground truth that makes automated translation verifiable and auditable.

Who is this for?

  • Software developers building multilingual products who need a consistent terminology reference
  • Translators and localization teams looking for a fast cross-language lookup tool
  • AI and machine learning researchers who need structured bilingual dictionary data
  • Language learners who want to see how a word translates across many languages at once

How does it work?

Dictionary entries are queried through a REST API. Submit any word in any supported language — the API returns all available translations in one response. Entries are stored in a database and served via Cloudflare Workers for low-latency global access.

Data is sourced from open dictionaries under Creative Commons licenses and extended through a community contribution workflow. All submitted translations are reviewed by human editors before being published.

Technical Stack

Frontend
Next.js, TypeScript, Tailwind CSS
API
Next.js API Routes (Cloudflare Workers)
Database
Supabase (PostgreSQL)
Deployment
Cloudflare Workers via opennextjs-cloudflare
Data Sources
CC-CEDICT, Wiktionary (CC BY-SA)
Supported Languages
11 languages (zh, en, fr, de, es, pt, it, ru, ar, ja, ko)

Open & Free to Use

The Multilingual Dictionary API is free for personal and non-commercial use. Commercial applications require an API key, available at no cost for low-volume usage. See the API Access page for tier details.

The source code is available on GitHub. Contributions of new translations are welcome through the submission form on the homepage.

Get an API KeyAPI Documentation