fast-is-equal
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Blazing-fast equality checks, minus the baggage. A lean, standalone alternative to Lodash's isEqual—because speed matters.
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# fast-is-equal
⚡️Blazing-fast equality checks, minus the baggage. A lean, standalone alternative to Lodash's `isEqual` - because speed matters.
[](https://badge.fury.io/js/fast-is-equal) [](https://github.com/JairajJangle/fast-is-equal/blob/main/LICENSE)  [](https://github.com/JairajJangle/fast-is-equal/actions/workflows/ci.yml) [](https://github.com/JairajJangle/fast-is-equal) [](https://github.com/JairajJangle/fast-is-equal) [](https://github.com/JairajJangle/fast-is-equal) [](https://github.com/JairajJangle/fast-is-equal) [](https://github.com/JairajJangle/fast-is-equal) [](https://github.com/JairajJangle/fast-is-equal)
## Why fast-is-equal?
- 🚀 **Lightning Speed**: Up to **55.84x faster** than Lodash's `isEqual` (average **11.73x faster** across 49 test cases).
- 🪶 **Lightweight**: Dependency-free, minimal footprint.
- 🔄 **Versatile**: Handles primitives, objects, arrays, Maps, Sets, typed arrays, circular references, and more.
- 🏆 **Proven**: Outperforms Lodash in **93.9%** of benchmark cases.
## Installation
Using yarn:
```bash
yarn add fast-is-equal
```
Using npm:
```bash
npm install fast-is-equal
```
## Usage
```typescript
import { fastIsEqual } from 'fast-is-equal';
console.log(fastIsEqual(1, 1)); // true
console.log(fastIsEqual({ a: 1 }, { a: 1 })); // true
console.log(fastIsEqual([1, 2], [1, 3])); // false
```
## Performance Benchmarks
`fast-is-equal` was tested against Lodash's `isEqual` across **49 diverse test cases** with **1,000,000 iterations each**. The results speak for themselves:
### Key Highlights
- **Average Speed**: `fastIsEqual` is **11.73x faster** (0.000172 ms vs. 0.002013 ms).
- **Win Rate**: Outperforms Lodash in **46/49 cases (93.9%)**.
- **Peak Performance**: Up to **55.84x faster** for large Sets.
### Top 10 Performance Gains
| Test Case | fastIsEqual (ms) | Lodash isEqual (ms) | Speed Boost |
| ----------------------- | ---------------- | ------------------- | ------------ |
| Large Set (100 items) | 0.000673 | 0.037564 | **55.84x** 🚀 |
| Map vs Set | 0.000018 | 0.000485 | **26.52x** 🚀 |
| Large Map (50 entries) | 0.001059 | 0.025756 | **24.32x** 🚀 |
| Map with primitives | 0.000092 | 0.001487 | **16.09x** 🚀 |
| Map (unequal) | 0.000092 | 0.001406 | **15.29x** 🚀 |
| Large TypedArray (1000) | 0.000944 | 0.013165 | **13.95x** 🚀 |
| ArrayBuffer (small) | 0.000092 | 0.001263 | **13.74x** 🚀 |
| Empty Set | 0.000058 | 0.000691 | **11.96x** 🚀 |
| Empty Map | 0.000058 | 0.000684 | **11.84x** 🚀 |
| Set of strings | 0.000082 | 0.000940 | **11.51x** 🚀 |
### Performance Across Categories
- **Primitives**: Competitive performance with smart optimizations for edge cases like NaN
- **Objects**: 1.59x–2.87x faster, with best gains on simple and nested structures
- **Arrays**: 1.24x–4.38x faster, excelling at primitive arrays and sparse arrays
- **TypedArrays**: 11.30x–13.95x faster, dramatically outperforming on all variants
- **Special Objects**: 8.63x–10.25x faster for Dates and RegExp
- **Collections**: 10.84x–55.84x faster for Maps and Sets, with exceptional gains on large collections
- **Circular References**: 3.04x–3.72x faster with optimized cycle detection
### Detailed Benchmark Results
Run `yarn benchmark` or `npm run benchmark` to test locally. Full results available in [benchmarks/results.txt](benchmarks/results.txt).
#### Edge Cases Where Lodash Wins
Only 3 cases where Lodash marginally outperforms (by less than 5%):
- String vs Number: 0.95x slower
- Large Numbers: 0.99x slower
- Boolean vs Number: 0.99x slower
These represent cross-type comparisons with negligible real-world impact.
## Features
- **Dependency-Free**: No bloat, just performance.
- **Comprehensive**: Supports all JavaScript types, including edge cases like circular references and typed arrays.
- **Optimized**: Fine-tuned for real-world use cases (e.g., API responses, state objects).
## License
MIT
## 🙏 Support the project
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