AI tool comparison
Pretty Fish vs X Island
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
X Island
Mac mission control for all your AI coding agent sessions at once
75%
Panel ship
—
Community
Free
Entry
X Island is a free macOS menu bar app that acts as a control panel for every AI coding agent session running on your machine — Claude Code, OpenAI Codex, Gemini CLI, Cursor, and others. It surfaces permission prompts, status updates, and session questions in a compact Dynamic Island-inspired overlay so you don't have to juggle terminal windows to babysit your agents. The core problem it solves is real and immediate: when you're running three concurrent agent sessions, each waiting on a different permission approval buried in different terminal panes, you miss them and sessions stall. X Island aggregates all of that into one place. You can approve requests, answer questions, and jump directly to the relevant terminal without losing context in your editor. It's local-first, requires no account, and has zero cloud dependency. The entire value proposition is reducing friction for the growing cohort of developers who now run AI coding agents continuously throughout their workday. Built by a solo indie developer and released as free software — the kind of quality-of-life tool that the agentic IDE category hasn't yet bothered to solve natively.
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.”
“I've been manually checking three terminal windows every 10 minutes to see if Claude Code is waiting on me. X Island fixes that with zero setup. This should be table stakes in every agentic IDE but nobody's built it natively yet — so this indie tool fills a real gap right now.”
“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.”
“This is a stop-gap for a problem that IDE makers will close in their next update cycle. Claude Code, Cursor, and VS Code all have roadmap items for better multi-agent coordination. Betting on a solo-built menubar app for your daily workflow feels risky when upstream tools will absorb the use case.”
“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.”
“The fact that this tool exists and has immediate traction signals how fast the 'run many agents in parallel' behavior has gone mainstream. We've crossed the threshold where developers expect to supervise fleets of AI workers — tooling will rapidly cluster around that expectation.”
“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.”
“Even for non-engineers running AI tools for content workflows, a unified notification layer for AI agent approvals is a UX pattern worth watching. The Dynamic Island aesthetic is clean and unintrusive — someone did the design work here.”
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