Most Divi 4 sites survive the move to Divi 5 — but the ones that break, break quietly. The migration itself is a guided conversion built into Divi. The risk lives in three places: third-party modules, child themes that touch PHP, and custom CSS aimed at old markup. Here's the audit I run before migrating any site, in the order I run it.
Step 1: Inventory what you're actually running
List every Divi-related extension on the site: third-party modules, Divi plugins, and your child theme. For each module, check the developer's site for a stated Divi 5 version. No stated support means assume it won't load — plan a replacement or a delay, don't hope.
Step 2: Grade your child theme
Open your child theme folder and look at what's in it. The grade is simple:
- style.css only (plus screenshot): low risk. Your styles ride along; some selectors may need updating where markup changed.
- functions.php with enqueues and minor hooks: medium risk. Test on staging; most hooks survive, but anything touching builder internals may not.
- Template overrides or custom modules in PHP: high risk. These reach into Divi 4's engine — the part Divi 5 replaced. Budget real rework time.
Step 3: Migrate on staging, then read the diff
Clone the site, run the Divi 5 migration on the clone, and then actually walk the pages — don't spot-check the homepage and declare victory. What you're looking for: layouts with missing sections (a third-party module didn't convert), spacing that drifted (CSS targeting old classes), and template parts that reverted to defaults (child theme overrides that no longer apply).
Step 4: Watch for the silent failures
The dangerous failures after a migration aren't white screens — they're the quiet ones: a contact form that stopped submitting, a hover state that vanished, a conditional section that no longer shows. This is where monitoring earns its keep. An activity log tells you what changed and when; conflict detection names the component when something does break. (Yes, I build tools for exactly this — Logger and Culprit — because migrations are where I needed them most.)
Frequently asked questions
How long does a Divi 4 to Divi 5 migration take?
A simple brochure site: an afternoon including testing. A site with third-party modules and a working child theme: plan a week of calendar time — most of it waiting on staging tests and module updates, not hands-on work.
Can I stay on Divi 4 for another year?
You can, and security support makes it survivable. But every month the third-party ecosystem tilts further toward Divi 5, so waiting doesn't shrink the work — it just moves it closer to being urgent.
What if my child theme developer is gone?
Common situation. If the theme is CSS-only, you're fine. If it has PHP customizations, have a Divi developer read it before you migrate — a one-hour review beats discovering the problem in production. This is exactly the kind of work I take on, if you want a second set of eyes.