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.

AI Voice Agents

Retell AI: Pricing, Features & Alternatives

Retell AI builds phone and web voice agents with a visual flow builder and an API. Instead of a platform fee, it bills each component per minute: $0.055 voice infrastructure, $0.015 standard TTS ($0.040 for ElevenLabs voices), $0.003 to $0.16 for the LLM and about $0.015 for US telephony. Typical totals land around $0.10 to $0.15 per minute. Add-ons such as knowledge base, denoising and PII removal cost extra. New accounts get $10 of free credit with no contract (prices as of August 2026).

Retell AI Pricing Plans (2026)

Plan	Price	Highlights
Pay as you goPopular	$0.07–0.31 / min, component-billed	$10 free credits to start · Visual agent builder · Phone and web calls
Enterprise	Custom	Volume discounts · Higher concurrency · Dedicated support

Pricing summary: Usage-based. Always confirm current pricing on the official site.

Key Retell AI Features

$10 free credits to start
Visual agent builder
Phone and web calls

Pros

+Transparent per-component billing
+No platform fee
+$10 free credit and no contract

Cons

−Add-ons stack up per minute
−Premium voices cost almost 3x standard
−Less low-level control than LiveKit

Best Retell AI Alternatives

Compare all

Vapi

Usage-based

Bland AI

Usage-based

LiveKit

Free · paid from $50/mo

Retell AI Compared

Retell AI vs LiveKit Retell AI vs Vapi Retell AI vs Bland AI

In-depth guideBest AI Voice Agent Platforms 2026: Vapi vs Retell vs LiveKit vs ElevenLabs vs BlandEvery voice platform advertises a per-minute price that isn't what you actually pay. True all-in cost, real-world latency, self-hosting, and compliance compared across the five that matter.

Retell AI FAQ

What is Retell AI used for?⌄

Retell AI is a ai voice agents tool. Voice agent platform with no platform fee: each component (voice infra, TTS, LLM, telephony) is billed separately per minute.

Is Retell AI free?⌄

Retell AI does not offer a permanent free tier.

How much does Retell AI cost?⌄

Retell AI uses usage-based (pay-as-you-go) pricing — see the official pricing page for current rates.

What are the best Retell AI alternatives?⌄

Popular Retell AI alternatives include Vapi, Bland AI, LiveKit. Compare pricing and features on our Retell AI alternatives page.