FormidableLabs/react-fast-compare

Health v2 · maintenance only

Adoption not part of the score

1666 stars · 54 forks observed · 2026-08-28

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

A tiny, fast deep-equality comparison library for JavaScript, forked from fast-deep-equal with extra handling for React-specific circular references like elements. It is designed primarily for use with React.memo and shouldComponentUpdate to prevent unnecessary re-renders.

Use cases

• deeply compare props in React.memo to avoid re-renders
• implement shouldComponentUpdate with deep equality checks
• compare nested objects and arrays for equality in JavaScript
• check equality of Date and RegExp objects
• compare values containing React elements without circular reference errors

When to choose

• you need deep equality checks in React.memo or shouldComponentUpdate after profiling confirms re-renders are a bottleneck
• you need a very small (<660 bytes) and fast general-purpose deep-equal function
• your data includes React elements or other circular references

When to avoid

• shallow comparison via default React.memo or PureComponent would suffice
• your objects contain circular references outside React elements
• you need equality checks for Maps, Sets, or other special structures not mentioned as supported

Facets

library · maturity maintenance

serialization frontend web-development developer-tools browser cross-platform deep-equality react performance-optimization react-memo should-component-update nodejs

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