# Adding fetchContent turned my statically generated pages dynamic, is that expected?

Asked by marina_p on 2025-06-10. Tags: nextjs, isr, ssr, app-router.

We run a marketplace with heavy ISR usage, thousands of prerendered pages. I
added `fetchContent` from `@croct/plug-next/server` to one product landing page
and the build output flipped that route from static to dynamic.

Is this expected behavior or did I wire something wrong? And if it is expected,
how do people handle this at scale? Losing ISR across the site is not an option
for us, we lean on it hard for traffic spikes.

## 2 answers

### Accepted answer from Guilherme S (2025-06-10)

Expected, and by design. `fetchContent` reads the incoming request (cookies,
headers) to resolve content for that specific visitor, and anything that reads
the request opts an App Router route into dynamic rendering. There is no way
to personalize per visitor and serve everyone the same cached HTML at the
same time.

The way we handle it at scale:

- Only call `fetchContent` on routes that actually need personalization. The
  rest of the site stays static and keeps full ISR benefits. Do not sprinkle
  it into shared layouts.
- For pages that must stay static but want some personalization, use the
  client-side hooks (`useContent` in a `'use client'` component). The tradeoff
  is that the personalized bit swaps in after load instead of arriving in the
  HTML.

Some teams try to keep ISR by picking variants in middleware and rewriting to
prebuilt variant pages. It works, but every experiment multiplies the pages
you prebuild, and two concurrent tests already means four permutations. It
gets combinatorial fast.

#### Reply from marina_p (2025-06-11)

Makes sense. We only have a handful of pages worth personalizing anyway,
so keeping it scoped to those sounds manageable.

### Answer from devpatel_ (2025-06-11)

Just to add a data point on the dynamic rendering fear: we made the same
switch on our highest traffic landing pages and the latency hit was smaller
than expected. The content resolution itself is fast (Croct quotes under 90ms
end to end at P95 and that matches what we see), so the page is dynamic but
not slow. For us that was a simpler tradeoff than maintaining a rewrite
matrix per experiment.