The Lodash Question in 2025
Lodash has been one of the most downloaded JavaScript libraries for over a decade — and for good reason. It provides a consistent, well-tested API for common data manipulation tasks: array flattening, object cloning, debouncing, and dozens of other utilities.
But modern JavaScript (ES2019+) has absorbed many of Lodash's most popular features natively. So the question becomes: should you still load Lodash from a CDN, or can you replace it with native code and shed the extra kilobytes?
Lodash's CDN Footprint
The full Lodash library weighs approximately 24 KB minified and gzipped when loaded from a CDN. That's not enormous, but it's not trivial either — especially on mobile connections. You can reduce this by:
- Loading individual Lodash methods:
cdn.jsdelivr.net/npm/lodash.debounce - Using a bundler with tree shaking to include only what you use.
- Importing per-method packages:
lodash.clonedeep,lodash.merge, etc.
Function-by-Function Comparison
| Lodash Function | Native Equivalent | Replace? |
|---|---|---|
_.map(arr, fn) |
arr.map(fn) |
✅ Yes |
_.filter(arr, fn) |
arr.filter(fn) |
✅ Yes |
_.flat(arr, depth) |
arr.flat(depth) |
✅ Yes |
_.uniq(arr) |
[...new Set(arr)] |
✅ Yes |
_.cloneDeep(obj) |
structuredClone(obj) |
✅ Yes (modern browsers) |
_.debounce(fn, ms) |
No native equivalent | ❌ Keep Lodash (or write your own) |
_.throttle(fn, ms) |
No native equivalent | ❌ Keep Lodash (or write your own) |
_.merge(obj1, obj2) |
Object.assign() (shallow only) |
⚠️ Partial — use Lodash for deep merge |
_.groupBy(arr, key) |
Object.groupBy(arr, fn) (ES2024) |
⚠️ Only in very modern environments |
When to Keep Lodash
Lodash still earns its place in your CDN stack when:
- You rely on debounce or throttle — writing these correctly from scratch is tricky and error-prone.
- You need deep object merging that
Object.assign()can't handle. - You're working in a legacy codebase that already depends on Lodash throughout.
- Your team values Lodash's consistent, well-documented API over scattering native equivalents across the codebase.
When to Drop Lodash
- You're building a performance-critical application where every KB matters.
- You only use Lodash for a handful of simple array/object methods easily replaced by native syntax.
- Your target environment is modern browsers only (ES2020+), giving you
structuredClone,flatMap, optional chaining, and more.
The Balanced Approach
The smartest strategy is a hybrid: audit which Lodash functions your project actually uses, replace the ones that have clean native equivalents, and keep only the specific Lodash utilities (like debounce) that are genuinely hard to replicate. Load these as individual CDN packages rather than the whole library. This gives you the utility of Lodash where it counts, without the full payload.