arasatasaygin/is.js

Health v2 · maintenance only

Flags: no_releases

Adoption not part of the score

9066 stars · 615 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

is.js is a general-purpose, dependency-free JavaScript micro check library for validating types, regexps, presence, time, and environment. It works in Node.js and the browser and provides not/all/any interfaces for its checks.

Use cases

• validate value types in javascript
• check if a string is a valid email or url
• detect browser and device environment
• check date properties like leap year or weekend
• validate phone numbers and zip codes

When to choose

• you need lightweight, zero-dependency runtime type and value checks
• you want a single library covering types, regexps, time, and environment detection
• you need checks that work in both Node.js and the browser

When to avoid

• you need static type checking rather than runtime checks
• you want a library with recent active development or new features
• you need schema or object-shape validation rather than simple checks

Facets

library · maturity maintenance

developer-tools form-handling web-development developer-tools browser cross-platform type-checking validation micro-library zero-dependency javascript nodejs

Member repositories

For agents

markdown · JSON · MCP: product_card(name="arasatasaygin/is.js")