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.

Polar vs Stripe: Which is Better in 2026?

Name: App Stack Builder
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Payment Gateway

Choosing between Polar and Stripe? Both are popular payment gateway tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack.

Polar is for: Developers selling SaaS, digital products and open-source sponsorships who want a merchant of record with volume tiers.

Stripe is for: Developers who want card and wallet payments through an API, with billing, tax and a merchant-of-record option from the same company.

Quick verdict

There’s no single winner; pick on your constraint. Choose Polar if you want a merchant of record and expect enough volume to use a lower-rate plan. Choose Stripe if you want to build checkout and billing through an API.

Polar vs Stripe — Side by Side

	Polar	Stripe
Category	Payment Gateway	Payment Gateway
What it is	Merchant of record for software	Payments platform
Merchant of record	Yes	No by default; yes with Managed Payments (+3.5%)
Online card fee	5% + 50¢ free; from 3.4% + 30¢ on paid plans	2.9% + 30¢ (US)
Monthly fee	$0, $20, $100 or $400	None
Built for	SaaS and digital products	Online businesses of any size
Pricing	From $20/mo	Usage-based
Starting price	From $20/mo	Pay-as-you-go
Free tier	—	—
Best for	Payment Gateway — merchant of record, developers, volume tiers	Payment Gateway — payments API, developers, global cards

Pros & Cons

Polar

Merchant of record (offloads tax/VAT)
Published lower rates as volume grows
Built for SaaS & digital goods
Open-source friendly

Free plan fee matches Paddle/Lemon (5%+50¢)
Younger than Stripe/Paddle

Stripe

Cards, ACH and wallets through one API
No setup or monthly fees
Merchant of record available through Managed Payments

You handle sales tax unless you add Managed Payments (+3.5%)
International cards and currency conversion add fees
$15 per dispute

Key Features Compared

Polar

Starter: free, 5% + 50¢ per transaction
Pro $20 a month at 3.8% + 40¢; Growth $100 at 3.6% + 35¢; Scale $400 at 3.4% + 30¢
+1.5% for non-US cards; no separate subscription fee on current plans
Disputes $15 each regardless of outcome; transaction fees not returned on refunds
Payouts at Stripe’s cost: $2 a month with active payouts, 0.25% + 25¢ per payout

Stripe

US cards and wallets: 2.9% + 30¢ per successful transaction; +0.5% manually entered, +1.5% international, +1% currency conversion
ACH Direct Debit: 0.8%; Billing: 0.8% of billing volume
Disputes: $15 per dispute
No setup or monthly fees on standard pricing
Managed Payments: Stripe becomes merchant of record for 3.5% on top of standard processing fees

Choose Polar if…

You want a merchant of record and expect enough volume to use a lower-rate plan.
You are a developer selling SaaS or digital products.
You want published rates for each volume tier.

Polar review & pricing

Choose Stripe if…

You want to build checkout and billing through an API.
You want to handle tax yourself now and add a merchant of record later.
You want cards, ACH and wallets from one account.

Stripe review & pricing

Frequently Asked Questions

Is Polar better than Stripe?⌄

What is the difference between Polar and Stripe?⌄

What it is — Polar: Merchant of record for software. Stripe: Payments platform. Merchant of record — Polar: Yes. Stripe: No by default; yes with Managed Payments (+3.5%). Online card fee — Polar: 5% + 50¢ free; from 3.4% + 30¢ on paid plans. Stripe: 2.9% + 30¢ (US). Monthly fee — Polar: $0, $20, $100 or $400. Stripe: None. Built for — Polar: SaaS and digital products. Stripe: Online businesses of any size.

Polar vs Stripe: which is cheaper?⌄

Polar pricing: From $20/mo. Stripe pricing: Usage-based. Confirm current pricing on each tool's official site, as plans change.

When should I skip both Polar and Stripe?⌄

Skip Polar if you will handle tax yourself for a lower card fee. Stripe charges 2.9% + 30¢ in the US. Skip Stripe if you want a merchant of record from day one at one flat rate. Paddle and Polar charge 5% + 50¢ with tax included.

Sources · tool facts checked November 2026