Modular Blocks: Building Flexible Pages in Contentstack

Modular blocks let editors assemble pages from reusable components

Editors want to build varied pages; engineers want structured, predictable content. Modular blocks are how Contentstack satisfies both — a curated set of reusable section types editors can stack in any order.

What Modular Blocks Are

A modular blocks field holds an ordered list of blocks, each its own mini content type — a Hero, a Feature Grid, a Quote, a CTA. Editors add, reorder, and remove blocks; your code knows exactly what each one contains.

When to Reach for Them

  • Landing pages with varied, marketing-driven layouts
  • Long-form pages mixing text, media, and callouts
  • Anywhere editors need flexibility but you need structure

For uniform content (a product spec), a fixed schema is better than modular blocks.

Each block maps to a component in your frontend

Rendering Blocks in the Frontend

Map each block type to a component and switch on the block key:

function Blocks({ blocks }) {
  return blocks.map((b, i) => {
    if (b.hero) return <Hero key={i} {...b.hero} />;
    if (b.feature_grid) return <FeatureGrid key={i} {...b.feature_grid} />;
    if (b.cta) return <CallToAction key={i} {...b.cta} />;
    return null;
  });
}

Keeping Blocks Maintainable

  1. Limit the catalogue — 8–12 well-designed blocks beat 40 overlapping ones.
  2. Name blocks by purpose, not appearance (testimonial, not purple_box).
  3. Validate required fields so a half-filled block never breaks the page.

Modular blocks are a contract: editors get freedom inside the lines you draw.

What to Learn Next

  • Global fields inside blocks for shared sub-structures
  • Live Preview so editors see blocks render in real time
  • GraphQL to fetch typed blocks efficiently

Arivanandhan Chitheshwaran