Assistant-ui vs Mastra
Assistant-ui vs Mastra, compared side by side on 21 data points: what each one does, how big it is, what it has raised, the tech running each site, and what users report. We score both out of 100 on traction, team and visibility: Assistant-ui is on 43/100 and Mastra on 77/100.
Where each one leads
Assistant-ui
Leads on none of the measures we hold for both companies.
Mastra
- our overall score: 77/100 against 43/100
- agent readiness: 58/100 against 51/100
- domain rating: 76/100 against 47/100
- funding raised: $35.5M against $500K
At a glance
| Measure | Assistant-ui | Mastra |
|---|---|---|
| What it is | Open-source React library for building production-grade AI chat interfaces. | An open-source TypeScript/JavaScript framework for building AI agents, from the creators of Gatsby. |
| Category | AI Chat Interface, Developer Tools, Open Source, React | Agentic AI, AI Agents, Developer Tools, Open Source |
| Sells toBusiness model | B2B | B2B |
| Offering | Software | Platform |
| Founded | 2024 | 2024 |
| Headquarters | San Francisco, United States | San Francisco, United States |
| Status | Active | Active |
Size, funding and growth
| Measure | Assistant-ui | Mastra |
|---|---|---|
| Employees | Not published | 53 |
| Headcount growthLast 12 months | Not published | +204.5% |
| Total funding | $500K | $35.5M |
| Latest round | Seed | Series A |
| LinkedIn followers | Not published | 6,591 |
StartupHub scores
Our own 0-100 ratings. They measure company strength and site quality, not which product suits you.
| Measure | Assistant-ui | Mastra |
|---|---|---|
| StartupHub scoreOur 0-100 rating | 43/100 | 77/100 |
| Traction | 28/100 | 70/100 |
| Team | 30/100 | 90/100 |
| Community | Not published | 38/100 |
| Search visibility | 22/100 | 68/100 |
| Quality | 55/100 | 78/100 |
| Agent readinessHow well an AI agent can read and act on the site | D (51/100) | D (58/100) |
| Domain ratingLink authority, 0-100 | 47/100 | 76/100 |
Technology
Detected on each public site, so it reflects the marketing stack as well as the product.
| Measure | Assistant-ui | Mastra |
|---|---|---|
| Hosting | Vercel | Vercel |
| CDN | Cloudflare | Vercel |
| CMS | Ghost | Not detected |
| Frameworks | Next.js, Tailwind CSS | Next.js, Tailwind CSS |
| Payments | Stripe | Not detected |
| Open source | Yes | Yes, 15,100 GitHub stars |
| Self-hostable | Yes | Yes |
Product and pricing
| Measure | Assistant-ui | Mastra |
|---|---|---|
| Key features | Not published | AI Agent Framework, Workflows, RAG, Evals, Memory & Tool Selection, Open Source & Modular |
What users say
| Measure | Assistant-ui | Mastra |
|---|---|---|
| Community ratingVisitor votes on StartupHub | Not published | 5.0/5 from 2 votes |
Assistant-ui vs Mastra: common questions
Which is better, Assistant-ui or Mastra?
On our 0-100 score Mastra rates higher (77/100 against 43/100). The score weights traction, team, visibility and profile completeness, so it reflects company strength rather than which product suits you. We compare the two on 21 data points above: read the rows that match what you are buying for.
How do Assistant-ui and Mastra compare on the numbers?
Mastra leads on our overall score (77/100 against 43/100), agent readiness (58/100 against 51/100), domain rating (76/100 against 47/100), funding raised ($35.5M against $500K).
Read the full Assistant-ui review and pricing or the Mastra review and pricing. You can also browse other Assistant-ui alternatives we track.