Three tools, three philosophies: text-first diagrams (Reladraw), canvas-first whiteboarding (Excalidraw), and code-as-diagram (Mermaid). This is an independent, community-written comparison — no affiliation with any of the projects.
Pick Excalidraw if you think visually and want to drag boxes around, especially for quick sketches, workshops and interviews.
Pick Mermaid if your diagrams already live inside Markdown docs, wikis or GitHub READMEs and must stay in sync with text.
Pick Reladraw if you want hand-drawn-style diagrams that stay editable as plain text, without learning a programming-ish syntax — positions are described relative to other shapes, not by coordinates.
| Reladraw | Excalidraw | Mermaid | |
|---|---|---|---|
| Core model | Text-first: every shape and its position described in plain sentences ("relative to") | Canvas-first: draw freely, scene stored as JSON | Code-as-diagram: declarative flowchart syntax rendered to SVG |
| Editing feel | Write and refine; no manual alignment | Drag, drop, sketch; fastest for freeform ideas | Write structured code; tool handles layout |
| Learning curve | Low — reads like instructions | Lowest — just draw | Moderate — a real syntax to learn |
| Version control | Excellent: diffs read like prose | Weak: JSON blobs are unreadable in diffs | Excellent: classic source diffs |
| Style | Hand-drawn look by default | Hand-drawn look by default | Clean, generated look |
| Complex layouts | Good for medium diagrams; relative positioning shines for maps/mind maps | Unlimited, but large scenes get messy manually | Strong for flowcharts; complex layouts may fight the auto-layout |
| Embedding | Render to SVG, paste anywhere | Export PNG/SVG or embed scenes | Native in GitHub/GitLab/Notion/Obsidian |
| Maturity | New (2026), evolving fast, small ecosystem | Mature, huge community | Mature, industry standard for docs |
| Best for | Docs-adjacent diagrams you'll revise often; people who hate fiddling with arrows | Brainstorming, teaching, quick visual notes | Pipelines, sequences, state machines in technical docs |
The honest case for Reladraw is revision workflow. In canvas tools, moving one box means dragging five arrows. In Mermaid, adding a branch can trigger a full re-layout you didn't want. Reladraw's relative positioning means you edit the statement ("the cache sits between the API and the database") instead of nudging pixels — the diagram stays legible through dozens of revisions.
The second win is diff readability in pull requests. A Reladraw source change reads like an edited sentence; nobody reviews a 400-line JSON scene diff.
Reladraw is young. The ecosystem (integrations, editor plugins, import/export) is small, and you may hit rough edges the other two grew out of years ago. If your team already standardized on Mermaid inside docs, switching cost outweighs the benefit. If your diagrams are inherently sketchy and collaborative, Excalidraw's canvas is simply faster.
No direct importer today. Short Mermaid flowcharts translate easily because the concepts map one-to-one; complex Excalidraw scenes are better redrawn — the point of Reladraw is describing structure, not tracing pixels.
Yes, the project is open source and the official playground runs in the browser.
If you document systems: Mermaid. If you sketch ideas with people: Excalidraw. If you maintain living diagrams that change every sprint: try Reladraw on one real diagram and see if the text-first workflow clicks.
Want to feel the text-first workflow? Grab a ready-made diagram from our gallery — see the AWS architecture, ER diagram or mind map templates, copy the source, and render it in the official playground.