silentmatt/expr-eval

Health v2 · maintenance only

Flags: no_releases

Adoption not part of the score

1351 stars · 269 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

expr-eval is a JavaScript library that parses and evaluates mathematical expressions, designed as a safer, math-oriented alternative to JavaScript's eval. Expressions containing variables can be evaluated with bound values, substituted, simplified, inspected for symbols, or compiled into native JavaScript functions, with support for custom functions and operator configuration.

Use cases

• evaluate user-typed math expressions safely in javascript without eval
• parse and calculate formulas with variables in node.js
• convert an expression string into a reusable javascript function
• evaluate spreadsheet-like formulas in the browser
• simplify or substitute variables in mathematical expressions
• allow custom operators and functions in a formula evaluator

When to choose

• you need to safely evaluate arithmetic or math expressions supplied by users instead of using eval
• you want a lightweight npm dependency focused purely on math expression parsing and evaluation
• you need to compile expressions once and evaluate them many times with different variable values
• you want to extend an expression language with your own javascript functions or disable operators

When to avoid

• you need a full computer algebra system with symbolic calculus or advanced algebra
• you need arbitrary code execution rather than pure math expressions
• you need heavy numerical computing, matrices, or units support better served by math.js or numeric libraries
• you are not working in a javascript runtime

Facets

library · maturity stable

parser math interpreter mathematics web-development parsers browser expression-evaluator expression-parser formula-evaluation safe-eval-alternative javascript npm nodejs

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