Pricing
Design for free. Unlock Chinilla AI and more with Pro.
Free
Learn and experiment with system design.
Build it yourself Everything you need to design, simulate, and share system architectures.
- Design any system on a drag-and-drop canvas with everything you need to start building What's included 7 component types: people, steps, storage, decisions, triggers, tools, channels Ready-made templates for workflows, process flows, and system design Grouping, mini-map, per-component sparklines 3 cloud projects + 20 version snapshots + JSON backup 4 themes (Sky, Chinilla, Dino, Plain) with light + dark
- Simulate it live watch packets flow and see how your system behaves under load using 8 programmable behaviors Behavior modes Passthrough, filter, split (weighted routing) Retry, circuit breaker, batch aggregation Replicate (fan-out), conditional routing Universal queueing + capacity + service-rate on every component Scrubbable timeline + per-component sparklines Little's Law metrics (λ, L, W, Lq, Wq, ρ) + hotspot pointer
- Spot what breaks at a glance red rings, lost counters, and persistent state indicators Visual signals on every run ⚡ TRIPPED / ⏱ PROBING badges (circuit breaker) ▦ BATCH ×N (current buffer size) Queue-fill ring around each component (green / amber / red) Floating ↓ IN / ↑ OUT / ✗ LOST / RETRY ×N pops on every event Bottleneck detection + runtime alert callouts show you exactly where the system is hurting
- Share what you built drop your design into a doc, slack, or interview round with one-click exports Export formats PNG + SVG (transparent or themed background) Mermaid + structured System Spec markdown Interactive preview links (recipients can pan/zoom/scrub) Repro bundle (full JSON: canvas + run params + seeds) Clipboard image, ready to paste anywhere
- Learn the basics guided beginner lessons Module 1 (beta) Build your first system step by step See bottlenecks form and fix them in real time 1 free interview-problem preview included + 1 free interview preview to try a real problem before committing
Pro
Design and learn systems with your AI partner.
Chinilla AI Your AI architecture partner What Chinilla AI can do Chat about your design + instant feedback Generate full systems from a prompt Upload docs, research, or whiteboard photos to get a diagram Connect a GitHub repo, get a diagram One-click AI-generated PRD from your design for ideas, designs, and docs. 300 credits/month Live usage, no surprises Predictable per-action pricing (see breakdown next to "per action") Live usage bar in the workspace + dashboard Resets monthly with your billing cycle No hidden token meters or model multipliers , per action Per-action cost Chat reply or explanation: 1 credit Iteration (add, connect, modify, remove): 3 credits Design generation: 5 credits GitHub repo analysis: 10 credits (deep multi-pass extraction) . Powered by Claude Sonnet 4.6
- Everything in Free
- Understand where it breaks stop guessing why your system fails. Run deep analysis Analyze your design Collapse Index stability score across N seeded runs Monte Carlo stress tests (outage drills, slow-component scenarios) Parameter sweep heatmaps (1D + 2D over capacity / serviceRate / weights) Timeline view (Spine for storytelling, Gantt for diagnosis) across many seeds and find the failure modes a single run can't show
- Master system design walk into your next interview already drilled on real problems Interview prep All interview templates (URL shortener, chat, pub/sub, rate limiter, file upload, notifications, more) Built-in checklist per template (requirements, scale, tradeoffs, failure modes) Full learning curriculum: System Design Fundamentals + Behaviors in Practice (free gets the IDE module) with the same checklists used in real-world design rounds
- Ship without limits scale up from "try it out" to "this is my workspace" with no caps Pro-only ceilings removed Unlimited cloud projects (free is capped at 3) Animated GIF export (share the run, not just the diagram) Subsystems: zoom into any component as its own diagram Every template unlocked (free gets a starter set)
- Work with your team design out loud on a shared canvas with real-time collab Team features Live multi-cursor canvas (owner + 1 guest) Casual mode for design reviews and pair-designing Interview mode: reveal-based checklist + private interviewer hints + Interviewer/Candidate roles Guests get a frozen copy of the project after the session built for design reviews and mock interviews
Compare plans
| Feature | Free | Pro |
|---|---|---|
| Building blocks | All 7 | All 7 |
| Templates | Starter set (lessons, examples, 1 interview) | Full library |
| Runtime simulation | ||
| Programmable behaviors | ||
| PNG + clipboard export | ||
| Animated GIF export | ||
| Mermaid + Spec export | ||
| Version snapshots | Up to 20 | Up to 20 |
| JSON backup + restore | ||
| Cloud projects | 3 | Unlimited |
| Publish interactive previews | ||
| Pro only | ||
| AI credits | 1 design/month | 300/month (Claude Sonnet 4.6) |
| Find weaknesses before they ship | ||
| Monte Carlo reliability testing | ||
| Parameter sweep (1D + 2D heatmaps) | ||
| Timeline view (Spine + Gantt) | ||
| Go from diagram to code | ||
| Zoom into any component | ||
| Generate a PRD in one click | ||
| Paste code, get a diagram | ||
| Upload research, visualize and publish | ||
| Learning modules | Module 1 (beta) | Module 1 + more soon |
| Live team collab (real-time canvas) | 1-on-1 (2 users) | |
| Interview mode (checklist + roles) | 10 templates | |
Questions
Can I use Chinilla without paying?
Yes. The free tier gives you the full canvas, all 7 component types, a starter set of templates, the runtime simulation (8 programmable behaviors, scrubbable timeline, state indicators), and exports (PNG, SVG, Mermaid, Spec markdown, JSON, interactive previews). 3 cloud projects, 20 snapshots, beginner lessons. No payment needed. Pro adds Chinilla AI (chat, design generation, GitHub repo import, PRD export), stability analysis (Collapse Index + Monte Carlo + parameter sweep), Timeline view (Spine + Gantt), animated GIF export, unlimited projects, subsystems, real-time team collab, and the full template library.
What counts as an AI credit?
AI actions are tiered by what the AI actually did. Chat replies and explanations are 1 credit. Iterations that modify the canvas (add, connect, modify, remove) are 3 credits. Full design generation is 5 credits. GitHub repo analysis is 10 credits (multi-pass extraction). Stability analysis and Monte Carlo run locally and never use credits. Deterministic exports (Mermaid, System Spec) and runtime simulation also do not use credits. Credits reset on your billing date each month.
Can I cancel anytime?
Yes. Cancel from your dashboard. You keep all designs (local and cloud) forever. AI features stop working but your data is always yours.
Do you train on my designs?
No. Your designs are never used for model training. AI features use Anthropic's Claude Sonnet 4.6 on a per-request basis with no data retention.
What is your refund policy?
We don't offer automatic refunds, but if something went wrong, contact us and we'll review your case.
