Stripe

Klarna

Stripe

Stripe charges a flat 2.9% + $0.30 per transaction. That's it.

No setup fees, no monthly fees, no hidden charges. The simplicity is the product.

When a customer pays on a website using Stripe, Stripe handles everything — fraud detection, currency conversion, bank transfers, tax calculation, compliance. The merchant just sees money arrive in their account.

On top of the core payments, Stripe has built an entire financial infrastructure stack. Billing for subscriptions, Connect for marketplace payments, Atlas for incorporating a company, Issuing for creating virtual cards, Treasury for banking-as-a-service, and Radar for fraud prevention.

They're basically building the financial plumbing for the entire internet.

Klarna

Klarna makes money from merchant fees and consumer interest. Merchants pay Klarna 3-6% of each transaction — they're willing to pay because Klarna increases conversion rates by 30%+ and average order values by 45%.

On "Pay in 4" (interest-free installments), Klarna makes money purely from merchant fees. On longer financing (6-36 months), Klarna charges consumers interest up to 25% APR.

Klarna also earns revenue from its shopping app (affiliate commissions when users discover and buy from merchants), and from its Klarna Card.

Stripe

Patrick Collison was 19. His brother John was 17.

They had already built and sold a company — Auctomatic, an eBay auction tool — for $5 million while still teenagers in Limerick, Ireland. Patrick went to MIT, John went to Harvard, and they both dropped out because they had a better idea.

The idea was embarrassingly obvious in hindsight. In 2010, accepting payments on the internet was a nightmare.

You had to get a merchant account, negotiate with a payment processor, deal with a gateway provider, handle PCI compliance, and write thousands of lines of code. It took weeks or months.

The Collisons thought it should take five minutes.

They built a simple API — seven lines of code — that let any developer start accepting credit card payments immediately. No merchant account.

No paperwork. No phone calls with banks.

Just paste seven lines of code and you're in business. They originally called it /dev/payments, then changed it to Stripe in 2011.

Peter Thiel and Elon Musk — the PayPal mafia — were among the first investors. Sequoia and Andreessen Horowitz piled in soon after.

The Collisons had built exactly what every developer on Earth had been wishing for.

Klarna

Sebastian Siemiatkowski, Niklas Adalberth, and Victor Jacobsson were students at the Stockholm School of Economics. In 2005, they entered a startup competition with an idea: let people buy things online and pay later.

At the time, online shopping was still new and most people were terrified of entering their credit card details on the internet. The idea was simple — Klarna would pay the merchant immediately, and the customer would get an invoice with 14-30 days to pay.

The competition judges hated it. The idea was dismissed as financially irresponsible and the team didn't win.

But Siemiatkowski pressed on. Swedish e-commerce was growing fast and merchants were desperate for any way to reduce cart abandonment.

Klarna's "pay after delivery" model was a hit because it shifted the risk — customers could receive the product, try it on, and only pay for what they kept.

The first customers were Swedish e-commerce merchants selling fashion and home goods. Klarna handled the invoicing, fraud detection, and collections.

Merchants saw conversion rates jump because customers were more willing to buy when they didn't have to pay immediately.

Stripe

Stripe grew almost entirely through developer love. They didn't hire a sales team for years.

They didn't run ads. They just built the best developer documentation anyone had ever seen and let word of mouth do the rest.

The developer-first strategy was deliberate. The Collisons realized that in a startup, the developer usually decides which payment provider to use.

If you make the developer happy, you win the company. Stripe's API documentation became legendary — clear, beautiful, with working code examples in every language.

They also grew by growing with their customers. Early Stripe customers included tiny startups that later became giants — Lyft, DoorDash, Instacart, Shopify.

As those companies scaled to billions in revenue, Stripe's processing volume scaled with them. Stripe didn't need to acquire new customers because its existing ones kept getting bigger.

The international expansion was methodical. Instead of launching everywhere at once like Uber, Stripe carefully added country after country, making sure each one worked perfectly with local payment methods, currencies, and regulations.

By 2024 they were processing payments in 195 countries.

Klarna

Klarna grew by being embedded at checkout. The strategy was to sign up the biggest online retailers and become a payment option alongside Visa and PayPal.

Once Klarna was at checkout, consumers discovered it organically. The "Pay in 4" button became ubiquitous across fashion, electronics, and home goods retailers.

The Klarna app became a growth engine beyond checkout. By building a shopping app where users could browse products, discover deals, and track deliveries, Klarna turned from a payment method into a shopping destination.

The app has 35+ million monthly active users who start their shopping journey inside Klarna before even visiting a retailer.

International expansion was aggressive. Starting in Sweden, Klarna rolled out across Europe, then into the US, UK, and Australia.

The US became the biggest growth market — American consumers were especially receptive to Pay in 4 as an alternative to credit cards. By 2023, Klarna had 34 million US users.

Stripe

Valuation whiplash. In 2021, Stripe hit a peak valuation of $95 billion during the fintech boom.

By 2023, they had to mark it down to $50 billion during the tech correction — a 47% drop that made headlines everywhere. Employees who had been paper millionaires suddenly weren't.

The valuation has since recovered to $91 billion after a secondary share sale in 2025, but those two years were rough for morale.

Competition is relentless. Adyen, the Dutch payments company, has been eating into Stripe's enterprise market.

Square (now Block) competes on the small business side. PayPal is everywhere.

New fintech players pop up constantly. The payments business has razor-thin margins and everyone is fighting for the same 2.9%.

Going public is the elephant in the room. Stripe has been expected to IPO for years.

Investors, employees, and the media keep asking when. The Collisons have consistently said they're in no rush, but with $8.7 billion raised and thousands of employees holding stock options, the pressure to provide liquidity is enormous.

As of 2025, they've opted for secondary sales instead of a public offering.

Klarna

The valuation collapse was humiliating. Klarna raised at a $46 billion valuation from SoftBank in 2021.

One year later, they raised a down round at $6.7 billion — an 85% haircut. It was the most dramatic valuation drop in fintech history.

Employee stock options were underwater. Siemiatkowski had to lay off 10% of the workforce.

The entire BNPL category went from hot to radioactive in months.

Credit losses are the existential risk. Klarna is lending money to consumers who want to buy things they can't afford to pay for right now.

When the economy slows, defaults rise. Klarna's credit losses hit $1 billion in 2022.

The company had to tighten underwriting significantly and pull back from riskier markets. The tension between growth (approve more loans) and profitability (reject risky borrowers) defines every quarter.

The IPO in 2025 was a comeback story but with caveats. Klarna went public at $15 billion — a major recovery from the $6.7 billion trough but still less than a third of its 2021 peak.

The company finally turned profitable by slashing costs with AI (replacing hundreds of customer service agents with AI chatbots) and tightening credit standards. But investors remain cautious about the BNPL model's long-term sustainability.

Stripe

Stripe Payments is the core — accept credit cards, debit cards, Apple Pay, Google Pay, and 135+ payment methods in 195 countries. Stripe Connect lets marketplaces and platforms pay out to sellers (Shopify, Lyft, DoorDash all use it).

Stripe Billing handles subscription and recurring billing. Stripe Atlas lets you incorporate a US company from anywhere in the world — fill out a form, get a Delaware C-corp, bank account, and tax ID in days.

Stripe Radar uses machine learning to block fraud in real time. Stripe Treasury lets platforms offer banking services to their customers.

Stripe Tax automatically calculates and collects sales tax in every jurisdiction.

Klarna

Pay in 4 is the signature product — split any purchase into four interest-free payments over six weeks. Pay in 30 lets customers receive the product first and pay within 30 days.

Financing offers longer-term payment plans with interest for larger purchases. The Klarna App is a shopping destination — browse deals, track orders, manage payments, and earn cashback.

The Klarna Card is a physical Visa card that lets users Pay in 4 anywhere. Klarna Creator is a platform for influencers to earn commissions sharing products.

Klarna AI is their customer service chatbot that handles two-thirds of support queries.

Stripe

Peter Thiel, Elon Musk, Sequoia Capital, Andreessen Horowitz, General Catalyst, Founders Fund, Tiger Global, GV (Google Ventures), Goldman Sachs, Baillie Gifford

Klarna

Sequoia Capital, SoftBank, Silver Lake, GIC, Atomico, Commonwealth Bank of Australia, Heartland