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.

Email VerificationFree tier

Reacher: Pricing, Features & Alternatives

Reacher is the hosted service around check-if-email-exists, an MIT-licensed Rust project with about 10K GitHub stars. It checks syntax, DNS and MX records, flags disposable and role addresses, and asks the receiving mail server over SMTP whether the mailbox exists, without sending anything. Self-hosting is free and runs as a Docker image, but it needs servers with outbound port 25 open and a clean IP reputation, which most clouds block by default. A hosted API with a small free tier and paid monthly plans is available for teams that would rather not manage that.

Reacher Pricing Plans (2026)

Plan	Price	Highlights
Self-hostedPopular	$0 (MIT)	Docker image or Rust library · Needs port 25 and clean IPs
Hosted API	Monthly plans	Managed SMTP probing · Small free tier

Pricing summary: Free · then usage-based. Always confirm current pricing on the official site.

Key Reacher Features

Docker image or Rust library
Needs port 25 and clean IPs

Pros

+MIT-licensed and self-hostable
+No per-check cost when self-hosted
+Transparent about how each check works

Cons

−Self-hosting needs port 25 and IPs with good reputation
−No list-cleaning UI or ESP integrations of the paid tools
−Catch-all and greylisting domains need extra handling

Best Reacher Alternatives

Compare all

ZeroBounce

Free · paid from $39/mo

Kickbox

Free · paid from $5/mo

NeverBounce

From $8/mo

Reacher Compared

Reacher vs ZeroBounce Reacher vs Kickbox Reacher vs NeverBounce

Reacher FAQ

What is Reacher used for?⌄

Reacher is a email verification tool. Open-source (MIT) email verification: checks syntax, MX records and the mailbox over SMTP without sending an email. Self-host or use the hosted API.

Is Reacher free?⌄

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

How much does Reacher cost?⌄

Reacher is free to use, with usage-based pricing on some features.

What are the best Reacher alternatives?⌄

Popular Reacher alternatives include ZeroBounce, Kickbox, NeverBounce. Compare pricing and features on our Reacher alternatives page.