Step 15

Performance budgets

nexa.toml can declare JS/CSS/image limits per page — unlike SEO warnings, this one genuinely blocks the build.

Declaring the budget

# nexa.toml
[performance]
maxInitialJS = 15000
maxCSS = 20000
maxImage = 200000

Absent by default (zero friction); declared, it's actually enforced.

What counts as "initial"

nexa build
# Presupuesto de rendimiento excedido (1 página(s)):
#   /products: maxInitialJS usa 18204 bytes, supera 15000
# Error: el build no cumple el presupuesto de nexa.toml

The framework assets the bootstrap always loads, plus chunks with the load strategy — the ones deferred on purpose (interaction/visible/idle/manual) don't count.