What is App Stack Builder?

App Stack Builder is a free AI-powered tool that helps founders and developers choose the right tech stack for their projects based on budget, app type, team size, and skill level.

What is the best tech stack for SaaS in 2026?

The best tech stack for SaaS in 2026 typically includes Next.js 16 for frontend, Supabase for database and auth, Vercel for hosting, Stripe for payments, and PostHog for analytics. App Stack Builder can generate a personalized recommendation based on your specific budget and requirements.

Is App Stack Builder free to use?

Yes, App Stack Builder is completely free to use. You can generate unlimited tech stack recommendations without any cost.

What types of apps can I build with the recommended stacks?

App Stack Builder supports various app types including SaaS applications, web apps, mobile apps, e-commerce stores, internal tools, and AI/ML products.

How much does a SaaS tech stack cost per month?

A modern SaaS tech stack can cost anywhere from $0-50/month for bootstrapped startups using free tiers, $100-300/month for growth-stage startups, to $500+/month for enterprise-ready infrastructure. App Stack Builder helps you find the best tools within your specific budget.

What is the best tech stack for solo founders?

For solo founders, we recommend Next.js + Vercel (free), Supabase (free tier), Supabase Auth (free), Stripe (pay as you go), and Plausible or PostHog for analytics. This stack can run your entire SaaS for under $50/month.

Can I export my tech stack recommendations?

Yes, you can export your tech stack recommendations as a PDF document or copy them to your clipboard. You can also share a link to your stack with others.

Agent Sandboxes & Code ExecutionFree tier

Modal: Pricing, Features & Alternatives

Modal lets you define infrastructure in Python and run it on demand: functions, batch jobs, web endpoints, GPU inference and, increasingly, sandboxes for agent-generated code. It sits in this category because its Sandbox API runs untrusted code in isolated containers billed by the second, at $0.00003942 per core-second and $0.00000667 per GiB-second. The same account can reach GPUs from T4s up to B200s when an agent needs one. Starter is $0 plus compute, with $30/month free and 3 seats. Team is $250/month plus compute, with $100 of credit and unlimited seats.

Modal Pricing Plans (2026)

Plan	Price	Highlights
StarterPopular	$0 + compute ($30 / month free credit)	3 workspace seats · Sandboxes, functions and GPUs · Per-second billing
Team	$250 / month + compute	$100 / month compute credit · Unlimited seats
Enterprise	Custom	Custom credits and support · Unlimited seats

Pricing summary: Free · paid from $250/mo. Always confirm current pricing on the official site.

Key Modal Features

3 workspace seats
Sandboxes, functions and GPUs
Per-second billing

Pros

+Sandboxes, GPUs and jobs on one platform and one bill
+Infrastructure as Python, with no YAML or Dockerfiles required
+$30/month free covers a lot of prototyping

Cons

−Python-first; other languages are second-class
−CPU sandbox rates are higher than dedicated sandbox vendors
−Team plan is a $250 step up

Best Modal Alternatives

Compare all

E2B

Free · paid from $150/mo

Vercel Sandbox

Free · then usage-based

Modal Compared

Modal vs E2B Modal vs Vercel Sandbox

Modal FAQ

What is Modal used for?⌄

Modal is a agent sandboxes & code execution tool. Serverless compute for Python, with sandboxes, GPUs and per-second billing. Starter is free with $30/month in compute credit.

Is Modal free?⌄

Yes — Modal has a free tier you can start with, and paid plans for more usage and features.

How much does Modal cost?⌄

Modal offers a free tier, with paid plans starting at $250/month. Some plans are usage-based (pay-as-you-go).

What are the best Modal alternatives?⌄

Popular Modal alternatives include E2B, Vercel Sandbox. Compare pricing and features on our Modal alternatives page.

Not sure if Modal fits your stack?

Get a free, AI-powered tech stack tailored to your budget, app type, and team size — including the best agent sandboxes & code execution pick for you.

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