Head to head
Stop guessing which one. Put them side by side.
Up to 4 tools, same rows for each: what it is, what it really costs, the trap, and how to wire it up. The URL carries your picks — send it to anyone.
EmergentGoogle Firebase Studioa0.dev
Quick read
- Free with no card: Google Firebase Studio.
| Field | Emergentemergent.sh | Google Firebase Studiofirebase.studio | a0.deva0.dev |
|---|---|---|---|
| What it is | Multi-agent system that plans, codes, tests and deploys, generating React or Next.js frontends on Node.js or FastAPI with MongoDB. It screenshots the running UI to verify its own work and asks clarifying questions. Every change pushes to your private GitHub repo, and Expo covers mobile. | Browser IDE built on Code OSS with an App Prototyping agent that turns a prompt into a Next.js or React app wired to Firebase. Supports Flutter and React Native workspaces plus full Git access to the generated code. Google announced its sunset on 19 March 2026. | Generates real React Native (Expo) projects — actual component files and navigation stacks, not a webview wrapper — with Convex or Supabase for data plus built-in AI inference and image-generation APIs. It runs the build, creates your App Store Connect listing, and uploads it for you. |
| Category | AI app builders | AI app builders | AI app builders |
| Cost tier | mixed | free | mixed |
| Pricing | Free 10 credits/mo · Standard about $17-20/mo (100 credits) · Pro about $167-200/mo (750 credits) · Enterprise custom | Free · 3 workspaces (10 with Google Developer Program, 30 Premium) · Blaze billing for App Hosting | Free (limited messages, 1 project) · Pro $20/mo (100 messages/day) · $50 / $100 / $200 and up |
| Why builders pick it | The most autonomous builder on this list — hand it a vague brief and it self-diagnoses and retries instead of stalling on the first error. Best for long unattended runs, not fast visual tweaks. | Was the cheapest way to get a Gemini-built app sitting directly on Firestore and Firebase Auth with no credit meter anywhere. Only relevant now for finishing and migrating workspaces you already have. | The shortest distance from prompt to an app sitting in review on both stores, because it owns the build and submission step that normally eats a week. Source export unlocks at Pro. |
| Watch out for | Live deployments cost roughly 50 credits a month on top of build credits, so the 10-credit free tier cannot host anything. Minor visual edits trigger 5-minute rebuilds, and browser previews expire after 30 minutes. | Shutting down. New workspaces and signups were disabled 22 June 2026, and the service shuts off 22 March 2027 with remaining data deleted. Google directs users to AI Studio or Antigravity; Firestore and Auth are unaffected. | The free plan caps you at one project and cannot export code — you need Pro to get the source out. Message caps, not compute, are the binding constraint on real work. |
| How to wire it up | not logged | not logged | Apple Developer Program ($99/yr) and Google Play ($25 one-time) accounts are still required. |
| Editor's pick | No | No | No |
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# Tool comparison — Emergent vs Google Firebase Studio vs a0.dev Source: Kbaise, a directory of tools that work with Lovable projects. Pick one and tell me why before writing any integration code. ## Emergent (emergent) - URL: https://emergent.sh - Category: AI app builders - Cost: mixed — Free 10 credits/mo · Standard about $17-20/mo (100 credits) · Pro about $167-200/mo (750 credits) · Enterprise custom - What it is: Multi-agent system that plans, codes, tests and deploys, generating React or Next.js frontends on Node.js or FastAPI with MongoDB. It screenshots the running UI to verify its own work and asks clarifying questions. Every change pushes to your private GitHub repo, and Expo covers mobile. - Why builders pick it: The most autonomous builder on this list — hand it a vague brief and it self-diagnoses and retries instead of stalling on the first error. Best for long unattended runs, not fast visual tweaks. - Trap: Live deployments cost roughly 50 credits a month on top of build credits, so the 10-credit free tier cannot host anything. Minor visual edits trigger 5-minute rebuilds, and browser previews expire after 30 minutes. - Full dossier: /api/public/tools/emergent ## Google Firebase Studio (google-firebase-studio) - URL: https://firebase.studio - Category: AI app builders - Cost: free — Free · 3 workspaces (10 with Google Developer Program, 30 Premium) · Blaze billing for App Hosting - What it is: Browser IDE built on Code OSS with an App Prototyping agent that turns a prompt into a Next.js or React app wired to Firebase. Supports Flutter and React Native workspaces plus full Git access to the generated code. Google announced its sunset on 19 March 2026. - Why builders pick it: Was the cheapest way to get a Gemini-built app sitting directly on Firestore and Firebase Auth with no credit meter anywhere. Only relevant now for finishing and migrating workspaces you already have. - Trap: Shutting down. New workspaces and signups were disabled 22 June 2026, and the service shuts off 22 March 2027 with remaining data deleted. Google directs users to AI Studio or Antigravity; Firestore and Auth are unaffected. - Full dossier: /api/public/tools/google-firebase-studio ## a0.dev (a0-dev) - URL: https://a0.dev - Category: AI app builders - Cost: mixed — Free (limited messages, 1 project) · Pro $20/mo (100 messages/day) · $50 / $100 / $200 and up - What it is: Generates real React Native (Expo) projects — actual component files and navigation stacks, not a webview wrapper — with Convex or Supabase for data plus built-in AI inference and image-generation APIs. It runs the build, creates your App Store Connect listing, and uploads it for you. - Why builders pick it: The shortest distance from prompt to an app sitting in review on both stores, because it owns the build and submission step that normally eats a week. Source export unlocks at Pro. - Trap: The free plan caps you at one project and cannot export code — you need Pro to get the source out. Message caps, not compute, are the binding constraint on real work. - Wiring: Apple Developer Program ($99/yr) and Google Play ($25 one-time) accounts are still required. - Full dossier: /api/public/tools/a0-dev ## Quick read - Free with no card: Google Firebase Studio. ## Rules 1. Prefer the free tier when no budget was stated, and say what the ceiling is. 2. Read the full dossier before integrating. 3. Fetch /api/public/models before writing any AI model ID.
Agents can fetch the same thing: GET /api/public/compare?slugs=emergent,google-firebase-studio,a0-dev