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.

Paddle vs Polar: Which is Better in 2026?

Name: App Stack Builder
Availability: InStock

Payment Gateway

Choosing between Paddle and Polar? 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.

Paddle is for: SaaS and software companies who want a merchant of record to handle sales tax, VAT, fraud and buyer support.

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

Quick verdict

There’s no single winner; pick on your constraint. Choose Paddle if you sell software globally and don’t want to register for VAT and sales tax. Choose Polar if you want a merchant of record and expect enough volume to use a lower-rate plan.

Paddle vs Polar — Side by Side

	Paddle	Polar
Category	Payment Gateway	Payment Gateway
What it is	Payments and billing platform	Merchant of record for software
Merchant of record	Yes	Yes
Online card fee	5% + 50¢, tax handling included	5% + 50¢ free; from 3.4% + 30¢ on paid plans
Monthly fee	None	$0, $20, $100 or $400
Built for	SaaS and software	SaaS and digital products
Pricing	Usage-based	From $20/mo
Starting price	Pay-as-you-go	From $20/mo
Free tier	—	—
Best for	Payment Gateway — merchant of record, SaaS, global tax	Payment Gateway — merchant of record, developers, volume tiers

Pros & Cons

Paddle

Merchant of record: collects and files sales tax for you
Fraud, chargebacks and buyer support included
No monthly or migration fees

5% + 50¢ costs more per sale than a plain gateway
Products under $10 need custom pricing
Custom rates only through sales

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

Key Features Compared

Paddle

Pay-as-you-go: 5% + 50¢ per checkout transaction
Merchant of record: collects the right tax rate and files sales tax returns for you
Payments, checkout, subscriptions and billing in one platform; fraud, chargebacks and buyer support included
No monthly, migration or hidden fees; no lock-in period
Custom pricing for high volume; contact Paddle for products under $10

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

Choose Paddle if…

You sell software globally and don’t want to register for VAT and sales tax.
You want chargebacks and buyer support handled for you.
You want subscriptions and checkout from the same vendor.

Paddle review & pricing

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

Frequently Asked Questions

Is Paddle better than Polar?⌄

What is the difference between Paddle and Polar?⌄

What it is — Paddle: Payments and billing platform. Polar: Merchant of record for software. Online card fee — Paddle: 5% + 50¢, tax handling included. Polar: 5% + 50¢ free; from 3.4% + 30¢ on paid plans. Monthly fee — Paddle: None. Polar: $0, $20, $100 or $400. Built for — Paddle: SaaS and software. Polar: SaaS and digital products.

Paddle vs Polar: which is cheaper?⌄

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

When should I skip both Paddle and Polar?⌄

Skip Paddle if you want a lower per-transaction rate as a merchant of record. Polar’s paid plans start at 3.8% + 40¢. Skip Polar if you will handle tax yourself for a lower card fee. Stripe charges 2.9% + 30¢ in the US.

Sources · tool facts checked November 2026