Grammar checker AI tools with API

LanguageTool is an AI grammar, spelling, and style checker supporting 30+ languages. It offers real‑time browser extensions, desktop and Word add‑ins, advanced Picky Mode, paraphrasing, and an API for developer integration.

Trinka AI is a privacy‑first grammar and language enhancement platform for academic and technical writing. It corrects grammar, punctuation, style, provides plagiarism checks, citation formatting, and multilingual support, integrating into Word, Chrome, and other editors.

TextGears is a grammar and spell checker with an API for automated proofreading, readability scoring, and text analysis. It supports multiple languages and offers both cloud-based and self-hosted deployment for integration into various business workflows.

RewriteBar is a macOS menu bar AI assistant that enhances writing by correcting grammar, changing styles, and translating text across applications. It supports 30 languages, streamlining the writing process for diverse users with a user-friendly interface.

Read Easy.ai transforms complex text into readable content for users. Word/Outlook add‑ins analyze manuscripts, while a Chrome extension simplifies webpages in multiple languages. Developers embed its API in React, Vue, Swift, WordPress for readability scoring and dyslexia‑friendly formatting.

Cmd-C.app is a macOS tool that offers real-time grammar, punctuation, and style corrections via a keyboard shortcut. It integrates with various platforms and provides detailed reviews and explanations for improved writing accuracy and productivity.

Scraib.app corrects grammar, tone, and style in any macOS app, rewriting selected text with a keyboard shortcut. Set global or per-app style rules and use preferred AI providers or a local runtime for consistent, in-context edits.