"Services or tools available for free without requiring an API key" matching MCP servers:

Provides access to synonyms and antonyms for words through the API Ninjas Thesaurus API, enabling vocabulary enhancement and word exploration.

Enables internationalization tasks such as language detection, hardcoded string extraction, translation JSON analysis, plural rule generation, and locale-aware formatting through the Model Context Protocol.

Enables AI agents to read and write JSON translation files (i18n, i18next, react-i18next) via the Model Context Protocol.

An MCP (Multi-Agent Conversation Protocol) Server that enables AI agents to interact with Google's Cloud Translation API for translating text between languages.

Provides dictionary lookup functionality through the API Ninjas Dictionary API, allowing users to search for word definitions and meanings through natural language queries.

Provides internationalization MCP tools enabling AI agents to perform translations, locale management, and i18n operations.

Enables interaction with XTRF translation management system through their Home Portal API. Provides access to XTRF's project management, translation workflow, and client portal functionalities via natural language interface.

An MCP server providing tools for speech-to-text, translation, language detection, question answering, and text-to-speech using Sarvam AI models, enabling multilingual voice agents.

Enables fetching YouTube video transcripts from any URL without API keys, browser, or OAuth, with honest error reporting for missing transcripts and support for multiple languages, formats, and resilient provider fallbacks.

Enables access to Humanizer APIs for text humanization with multiple models including basic, easy-use, and multi-language support. Requires API key authentication.

Model Context Protocol (MCP) server for the Royal Spanish Academy (RAE) API. It allows language models to interact with RAE's dictionary and linguistic resources.

Lets AI agents read and write the Calibre Ebook Translator plugin's translation cache chunk by chunk, enabling direct book translation workflows without manual copy-paste.

Enables AI agents to conjugate verbs in 14 European languages via a hosted Rust API, requiring only a free API key.

Enables AI agents to format, validate, and compare Japanese bank-transfer account names for Zengin compatibility, including half-width katakana conversion, legal-entity abbreviation rules, length checks, and reconciliation matching. All tools are read-only and offline.

Enables AI agents to repair OCR-mangled Japanese dates only when calendar validation confirms the corrected result, and to check individual dates against their era ranges.

An MCP server that integrates Kagi Translate as tools for translation, URL translation, and proofreading, requiring a Kagi API key.

An MCP server that provides access to the Similar Words API, allowing users to search for and retrieve semantically related words. It enables language-based applications to query word similarities and relationships through a standardized interface.

Connects MCP clients to a self-hosted LanguageTool HTTP instance over stdio, letting them proofread text for spelling, grammar, punctuation and style issues and to list the languages the instance supports. Returns a Markdown report grouped by category with correction suggestions, and supports language selection, stricter checking, and rule enabling/disabling.

Enables AI agents to identify what language text is written in, returning top matches, confidence scores, script detection, and character statistics via a pay-per-call x402 API without requiring an API key.

Enables Chinese text segmentation using the jieba library with support for precise, full, and search engine modes. Provides natural language access to professional Chinese word segmentation capabilities through MCP protocol.

Provides translation services for technical terms across English, Spanish, and German via MCP tools for search and translation.

Enables AI agents, developers, and CI pipelines to run deterministic, offline localization QA — pseudolocalization, locale linting for separators/dates/placeholders/RTL, and glossary enforcement across 20 locales — without any network access or API key. When an OpenAI-compatible endpoint is configured, it can also translate into multiple locales and lint the results, or otherwise emit structured translation jobs instead of fabricating translations.

Enables scanning game or mod directories for translatable text files, invoking OpenAI-compatible AI translation services, and writing Chinese translations to an isolated output directory without modifying original files.

Enables MCP clients to run text tasks such as asking, rewriting, summarizing, translating, and classifying through free web chat providers on stdio, without needing an API key. It sits on the same provider drivers as the HTTP surface, so a provider added once works across both.

MCP server for the SELISE Blocks UILM API, providing translation key management tools for Claude Code, Cursor, and any MCP-compatible client.

Enables bidirectional lookup of Mi'kmaq and English words with definitions and examples, and provides tools for learning and dictionary statistics, integrating seamlessly with AI-powered IDEs.

Search Japanese onomatopoeia by scene, not by spelling. 161 entries with nuance explained in Japanese and English. Fully offline MCP server, no API key required.

AI localization from your editor — translate an app's string files into 46 languages with placeholder-safe, reproducible output. Eleven formats (JSON, .arb, .po, .strings, Android XML and more), and every translation is read back and checked before it lands.

A local-first multilingual dictionary, thesaurus, translation, lexical-relations, semantic-neighbour, and English wordplay server for the Model Context Protocol (MCP). It operates fully offline with read-only query access and no data mutation while running.

MCP server for translating PDFs using pdf2zh-next, preserving document context by extracting all text segments for LLM translation at once.