Migrate Mermaid Diagrams from Confluence Data Center to Cloud

Rahul_RVS

🚀 Overview

When you move a Confluence site from Data Center to Cloud using Atlassian's Confluence Cloud Migration Assistant (CCMA), your pages come across fine — but CCMA has no way to automatically convert macros from one app to another. Any page that used an old Data Center Mermaid plugin — Mermaid Diagrams for Confluence (Stratus Add-ons) or Mermaid Charts & Diagrams for Confluence (weweave) — arrives on Cloud as a broken placeholder reading "Error loading the extension!" The diagram source text is still there, just orphaned from any macro that knows how to render it.

We at RVS have built a migration utility which comes along our Confluence app →

Mermaid Diagrams & Charts for Confluence

Our inbuilt utility, Mermaid — Migrate from Data Center finds every one of those broken diagrams across your entire site and re-wires them into this app's own macro — so the diagrams render again, with zero copy-pasting.

✨ Key Features

🔀 Two Legacy Plugins Supported — works with either Stratus Add-ons' or weweave's Data Center Mermaid macro; pick which one this site used from a dropdown before scanning

🔍 Site-Wide Scan — checks every page on the site (read-only) for old Data Center diagrams

🧪 Test Run (changes nothing) — preview exactly what will convert before a single page is touched

🔄 One-Click Convert — safely rewires old macros into the current Cloud macro automatically

📝 Ordinary Page History — every conversion is just a normal page edit, fully visible and revertable

♻️ Safe to Re-run — already-migrated pages are simply reported as done, nothing is converted twice

🎯 Precise, Never Guessed — only the recognized macro(s) for the plugin you selected convert; anything ambiguous is skipped and flagged for manual review

📊 Detailed Results — see exactly how many pages converted, how many were already done, and which need attention

🛠️ How to Migrate Your Diagrams

Step 1 — Open the Migration Page
In Confluence, go to Settings (⚙️) → Apps → Manage apps, then find Mermaid — Migrate from Data Center in the left sidebar under this app.

Step 2 — Choose Your Legacy Plugin
Select which Data Center Mermaid plugin this site actually used: Mermaid Diagrams for Confluence (Stratus Add-ons) or Mermaid Charts & Diagrams for Confluence (weweave). Each stores its diagrams differently, so only the matching plugin's macros will be scanned and converted.

 

Step 3 — Find Old Diagrams
Click Find old diagrams. This scans the whole site read-only and reports something like "Checked 4,213 pages and found 12 old diagrams on 9 pages." If nothing is found, you'll see "No old diagrams found — there is nothing to migrate."

Step 4 — Run a Test First
Click Test run (changes nothing). This runs the real conversion logic without saving anything, so you can confirm the numbers before committing to real page edits.

Step 5 — Convert
Click Convert diagrams. This performs the actual conversion, saving a new page version for every affected page.

⚙️ What Each Step Does

Step	What It Does
Choose plugin	Tells the tool which vendor's macro name(s) and storage shape to look for — Stratus and weweave store diagrams differently
Find old diagrams	Scans every page on the site (read-only) and lists which pages contain the selected plugin's old macros
Test run (changes nothing)	Runs the exact same conversion logic without saving anything — a risk-free preview
Convert diagrams	Performs the real conversion and saves a new page version for each affected page
Scan again	Re-checks the site after converting, to confirm nothing was missed

🎯 Common Use Cases

• Post-CCMA Cleanup — repair diagrams left broken after running Atlassian's Confluence Cloud Migration Assistant
• Phased Migrations — re-run the scan periodically as more spaces get migrated over time
• Migration Audits — get a site-wide count of exactly how many legacy diagrams still need conversion
• Pre-Cutover Verification — confirm zero old diagrams remain before decommissioning Data Center for good

⚠️ Best Practices

✔ Confirm which legacy plugin (Stratus vs. weweave) this site actually used before scanning — picking the wrong one will find nothing

✔ Always run Test run before Convert diagrams — check the numbers before touching real pages

✔ Ask your team not to edit the affected pages until migration finishes, to avoid version conflicts

✔ Read "What exactly will this change?" before you start — some old visual styling (shadows, rounded corners, connector styles) isn't preserved

✔ Run Scan again after converting to confirm the site is fully clean

✔ If a page shows "Unknown macro: [old macro name]" after editing, it was mid-edit during the DC migration — open Edit, then use the "…" menu → "Revert to last published version" instead of saving

✔ You'll need Confluence site-admin permissions to access this page

Try the app now → Mermaid Diagrams & Charts for Confluence