Laravel Eloquent Performance Cheat Sheet

N+1 queries, chunking and the memory limits Eloquent hides

Eloquent makes the expensive query look identical to the cheap one. These are the patterns that keep a convenient ORM from becoming the bottleneck.

Category: Laravel Difficulty: Intermediate Version: 1.0 Updated: October 9, 2025 Author: Sabir

Loading relations

Call	Does
`Post::with("author")->get()`	Eager load — 2 queries instead of N+1
`Post::with("comments.author")->get()`	Nested eager load
`Post::with(["author:id,name"])->get()`	Select only the columns you need
`Post::withCount("comments")->get()`	A count without loading the rows
`Post::withExists("comments")->get()`	Cheaper still when you only need a boolean
`$posts->load("tags")`	Eager load after the fact on an existing collection
`Model::preventLazyLoading()`	Throws on lazy loads in dev — the fastest way to find them all

Iterating large sets

Method	Memory	Caveat
`get()`	Everything at once	Fine until the table grows
`chunk(500, fn)`	One chunk at a time	MODIFYING rows inside shifts the offsets
`chunkById(500, fn)`	One chunk at a time	The safe choice when you write during the loop
`lazy()`	One model at a time	Chunks underneath; behaves like a generator
`cursor()`	One model at a time	A single held connection — not for slow per-row work

Finding an N+1 in one run

Call Model::preventLazyLoading(! app()->isProduction()) in a service provider. Every lazy load then throws in local and staging with the exact relation and model named, and stays silent in production. It finds in one page load what reading the query log finds in an afternoon.

Code examples

Find every N+1 in one page load PHP

Throws on any lazy load outside production, naming the exact relation and model.

use Illuminate\Database\Eloquent\Model;

public function boot(): void
{
    // Loud in local and staging, silent in production
    Model::preventLazyLoading(! app()->isProduction());
}

// Then the fix is mechanical:
$posts = Post::query()
    ->with(['author:id,name', 'tags:id,name'])   // only the columns used
    ->withCount('comments')                       // a count, not the rows
    ->latest()
    ->paginate(20);

// Writing while iterating? chunkById, never chunk — chunk() shifts its
// own offsets when the rows it already passed are modified.
Post::where('needs_reindex', true)
    ->chunkById(500, fn ($rows) => $rows->each->reindex());

FAQs

What is the fastest way to find N+1 queries?

Model::preventLazyLoading(! app()->isProduction()) in a service provider. Every lazy load then throws in local and staging, naming the exact model and relation, and stays silent in production.

chunk or chunkById?

chunkById whenever the loop modifies the rows it is reading. Plain chunk() uses offsets, and rows changing under it shift those offsets so records get skipped.