TL;DR
Notion has native Mermaid in code blocks now, but the default look is the same pastel render you've seen everywhere, and there's no theme override. This post walks through the four approaches that actually work in 2026 — native code block, static image upload, public hot-linkable image, and live-updating embed — with a comparison table at the end so you can pick by trade-off. There's a shortcut at the 70% mark if you'd rather skip the maintenance.
Why this article exists
Two years ago, "embed Mermaid in Notion" was a search query that returned twenty Stack Overflow threads and zero working answers. Then Notion shipped native mermaid code-block rendering, and the question went quiet.
But the question didn't go away — it shifted. The native renderer works, but it gives you exactly one look: Mermaid's default theme, no overrides, no themeVariables honored. The moment you want your team's Notion docs to feel like a finished product instead of a hackathon scratchpad, you're back to needing a workaround.
