textlint and textlens
These are complements: textlint provides extensible linting rules for text quality issues, while textlens offers standalone readability metrics and NLP analysis that could be integrated as a custom textlint plugin or used alongside it for comprehensive text evaluation.
About textlint
textlint/textlint
textlint is the pluggable linter for natural language text.
Built on an AST-based architecture similar to ESLint, textlint parses documents into abstract syntax trees and applies rules through a plugin system with zero bundled rules—users install only needed rule packages. It supports Markdown and plain text natively, with extensible processor plugins enabling linting of HTML, reStructuredText, and other formats, plus customizable formatters and automatic --fix capabilities.
About textlens
ckmtools/textlens
Zero-dependency TypeScript text analysis and readability toolkit. 8 readability formulas, sentiment analysis, keyword extraction, SEO scoring, summarization, and CLI.
Scores updated daily from GitHub, PyPI, and npm data. How scores work