AI tool comparison
Pretty Fish vs Roo Code
Which one should you ship with? Here is the side-by-side panel verdict, pricing read, reviewer split, and community vote comparison.
Developer Tools
Pretty Fish
Free, beautiful Mermaid diagram editor that works offline
75%
Panel ship
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Community
Free
Entry
Pretty Fish is a free, open-source Mermaid diagram editor with live preview, 5 built-in themes, multi-page workspaces, and one-click SVG/PNG export. It works offline as a Progressive Web App (PWA) and requires no account, no login, and no installation. It supports all 14+ Mermaid diagram types including flowcharts, sequence diagrams, Gantt charts, entity-relationship diagrams, and Git graphs. The editor includes syntax highlighting, auto-completion, instant error feedback, and a clean split-pane layout. The multi-page workspace lets you manage entire diagram projects in a single session. Export quality is excellent — SVG output is clean and scaling-ready for use in presentations, docs, or design systems. Pretty Fish hit Hacker News front page today with 128 points and has the makings of the go-to Mermaid editor for developers who generate diagrams from AI-assisted documentation workflows. With LLMs increasingly generating Mermaid syntax in their outputs, having a polished renderer and editor matters more than ever.
Developer Tools
Roo Code
A full AI dev team in your VS Code — Code, Architect, Debug & custom modes
75%
Panel ship
—
Community
Free
Entry
Roo Code is a VS Code extension that embeds a configurable AI development team directly into your editor. Rather than offering a single generic assistant, it ships with specialized work modes — Code Mode for everyday programming, Architect Mode for system planning and migrations, Debug Mode for root cause analysis, and Ask Mode for quick explanations. Teams can also define custom modes for project-specific workflows. The extension integrates with MCP (Model Context Protocol) servers and supports bring-your-own API keys for whatever underlying model you prefer. This keeps the tool model-agnostic, letting teams swap between Anthropic, OpenAI, and open-source models without lock-in. After the original creators pivoted to a commercial product (Roomote), Roo Code transitioned to full community maintenance — but the codebase remains healthy under Apache 2.0. What separates Roo Code from tools like Copilot or Cursor is its multi-mode philosophy: different tasks demand different AI personas. Architect Mode nudges the model toward planning, trade-offs, and long-horizon thinking. Debug Mode roots it in evidence and stack traces. It's a small design choice that meaningfully changes how developers interact with AI across a project lifecycle.
Reviewer scorecard
“The official Mermaid live editor is clunky and slow. Pretty Fish loads instantly, works offline, and the multi-page workspace means I can manage all my architecture diagrams in one place. Bookmarking this immediately as my default Mermaid editor.”
“The multi-mode approach is genuinely underrated — switching to Architect Mode feels like talking to a different person and that's a good thing. MCP support and model-agnosticism mean you're not boxed in. Once you add custom modes for your team's workflows this becomes indispensable.”
“It's a genuinely nice editor but it's solving a niche problem — most devs who need Mermaid diagrams already use VS Code extensions or embed them in Notion. And with no backend, there's no collaboration or sharing story, which limits its use in team workflows.”
“The original creators left for a commercial product, which is a yellow flag for long-term maintenance. Community-led projects in this space often stagnate within 6 months. Cursor already does 80% of this without any setup friction.”
“As AI tools increasingly output Mermaid syntax to explain architectures and flows, the need for a great rendering environment grows. Pretty Fish positions itself at the intersection of AI-generated diagrams and human editing — that's a well-timed niche.”
“Mode-based AI interaction is an important UX pattern — the idea that your assistant should shift personality and priorities based on the task at hand. Roo Code is proving the concept works before the big IDEs fully implement it.”
“Five beautiful themes and clean SVG exports mean I can finally use Mermaid diagrams in client-facing presentations without them looking like developer scratch notes. This is the Mermaid editor I've always wanted and the zero-friction setup seals it.”
“As someone who uses editors for non-code work too, the Ask Mode is surprisingly useful for quick in-editor research and writing. The extensibility means you could build a Markdown editing mode or doc-writing mode without much effort.”
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