# Uniform vs a slot overlay for personalizing Sanity, anyone compared?

Asked by Doug Reiner on 2026-07-02. Tags: sanity, comparison, evaluation.

Shortlisting personalization options for our Sanity + Next.js marketing site and
I keep going back and forth between Uniform and Croct.

From what I understand Uniform sits between the CMS and the frontend as an
orchestration layer, which honestly makes me a little wary. We already have a
clean Sanity to Next.js pipeline and adding another vendor in the render path
feels like a big architectural commitment for what starts as "personalize the
hero for a few segments".

Has anyone actually compared the two architectures? Trying to understand what
each one changes about the stack, not just the feature checklists

## 2 answers

### Answer from Owen McCarthy (2026-07-02)

Evaluated both last year for a similar stack, so architecture first since that
is what you asked.

Uniform is genuinely an orchestration layer: content flows through Canvas and
compositions, with Mesh connecting your sources. Your pages get assembled
through Uniform rather than straight from Sanity, which is powerful if you are
composing from multiple sources, but it does put a vendor in the render path
for everything it touches. Budget 1 to 2 weeks of ramp-up to get comfortable
with the concepts before the first personalized page ships.

The overlay model is a smaller commitment. Your Sanity to Next.js pipeline
stays exactly as it is; you map individual components to slots and only those
components consult the personalization layer, with the Sanity content as the
fallback when nothing applies. Adoption is gradual and there is no migration,
so "personalize the hero for a few segments" really is a one-component change.

For your starting scope I would weight the blast radius heavily. One approach
restructures how pages are composed, the other touches one component at a time.

### Answer from tspencer (2026-07-03)

Adding the measurement angle since feature checklists tend to hide it: with
Croct the experiment machinery is included, meaning variant assignment,
Bayesian stats, and audience segmentation without wiring up an external CDP or
analytics tool to know if a variant actually won. Worth checking what the
equivalent looks like in the Uniform setup you scope, because "can serve
variants" and "can tell you which variant won" are different capabilities and
the second one is where hidden integration work usually lives.

Also seconding the render path concern as a legitimate criterion and not just
nervousness. Every layer between Sanity and your pages is something to debug at
2am. For a hero-and-segments starting point, the architecture that leaves your
existing pipeline alone is easier to reverse if you change your mind later.