Polar

Polar (polar.sh) is an open-source, developer-first Merchant of Record that handles billing, sales tax, and digital-product delivery for software companies — at a headline rate of 4% + $0.40 per transaction. We rate it 83/100 — the most credible open-source alternative to Lemon Squeezy and Paddle in 2026, with a clear caveat about international + subscription surcharges that bring real-world rates closer to 6% + $0.40.

What is Polar?

Polar is built by Polar Software AB, a Stockholm-based startup co-founded by Birk Jernström in 2022. The full source code lives at polarsource/polar under an Apache License 2.0, and the project crossed 5,300 GitHub stars in early 2026 with more than 1,500 active members in its Discord community. Polar v1.0 — the version that flipped the company from an open-source funding tool to a full Merchant of Record — shipped on September 15, 2024.

Polar's distinguishing pitch is straightforward: every other modern MoR (Lemon Squeezy, Paddle, Gumroad) is a closed black box. Polar is the only one whose entire pricing engine, checkout flow, webhook system and tax pipeline is fully auditable on GitHub, plus it ships first-party SDKs for Better Auth, Next.js, Supabase, Encore.ts, and Laravel that no other MoR currently matches.

Key Features of Polar

• Merchant of Record by default: Polar is the legal seller for every transaction, meaning it handles VAT, US sales tax, and EU OSS reporting in 50+ jurisdictions automatically — you receive net payouts via Stripe Connect Express to about 120 countries.
• Built-in entitlements: Out of the box, a paid product can grant license keys, private GitHub repository access, Discord roles, gated file downloads, and custom benefits via webhooks — the heaviest reason developer-tool founders pick Polar over Stripe directly.
• Subscriptions, one-off, and usage billing: Polar supports monthly/yearly plans, seat-based proration directly from the customer portal, one-time digital products, and event-based usage billing with API ingestion.
• First-party Better Auth plugin: The official @polar-sh/better-auth npm package auto-creates a Polar customer when a Better Auth user signs up, exposes a checkout() helper, and gives users a self-serve portal — turning a typical Stripe + tax + auth wiring job into about 30 lines of TypeScript.
• Open-source, self-hostable core: Apache-2.0 backend (FastAPI + Postgres) and Next.js frontend; you can run the full stack locally for development and inspect every cent of the fee math against the production codebase.
• Polar Sandbox + LLM-friendly docs: A free sandbox environment mirrors production, and Polar maintains a /docs/llms-full.txt bundle so AI coding agents like Cursor, Claude Code and Codex can wire up checkout flows from natural-language prompts in one shot.
• Public REST API + Webhooks: Every object — products, customers, subscriptions, benefits, license keys — is exposed via REST with TypeScript and Python SDKs, plus signed webhooks for events like order.paid and subscription.canceled.

What Users Say About Polar

Sentiment on Hacker News, r/SaaS and r/webdev is mostly positive but with a clear caveat about real-world fees. The Show HN thread for Polar's v1.0 launch praised the team for being the first credible open-source MoR — multiple commenters noted that the Apache-2.0 license meant they could finally trust the billing stack they were betting their business on. Better Auth founder Bereket Engida and several Vercel and Supabase engineers publicly endorsed the platform on X within weeks of v1.0.

The recurring complaint is the gap between the headline price and the effective rate. Independent breakdowns (notably UserJot and Dodo Payments' competitive review) point out that international cards add 1.5%, subscriptions add 0.5%, and chargebacks cost a flat $15 — so a SaaS with 40% international subscribers is effectively paying around 6% + $0.40, a 50% premium over the "4%" sticker. A February 2026 Reddit thread titled "Paddle is slow and Polar.sh is non-responsive" flagged support latency under 24 hours as a real pain point during disputes.

Polar Pricing

There is no monthly subscription, no minimum, and no per-seat fee. Every dollar of cost is a transaction fee. The full live fee schedule lives at polar.sh/docs/merchant-of-record/fees and looks like this:

Fee Type	Rate	Notes
Base transaction fee	4% + $0.40	Applied to every successful payment.
International card surcharge	+1.5%	Any card issued outside your billing country.
Subscription surcharge	+0.5%	Recurring payments only — one-off purchases are exempt.
Chargeback fee	$15 flat	Refunded if you win the dispute.
Payout fee	Stripe pass-through	Roughly $2 per international wire, free for ACH.

For a US-only SaaS selling $30/month subscriptions to domestic customers, the all-in cost is about 4.9% per transaction. For a developer tool with 50% international subscribers, expect closer to 6.0% + $0.40.

Who Should Use Polar?

Best for: Solo developers and small teams shipping VS Code / Cursor / JetBrains extensions, AI agents, npm libraries with a paid tier, GitHub-gated open-source products, and indie SaaS founders who want one bill instead of stitching together Stripe + Stripe Tax + Anrok + Lemon Squeezy. The Better Auth and Supabase plugins make it especially compelling for the modern Next.js + Postgres stack.

Not ideal for: High-volume SaaS doing $1M+ ARR with mostly international subscribers — at that scale a direct Stripe + Anrok or Stripe + TaxJar combination usually beats 6% all-in. Also a poor fit for physical-goods commerce (use Shopify) or for teams already deeply invested in Paddle/Lemon Squeezy without a real reason to migrate.

Pros and Cons

Pros:

• Only MoR in the market with a fully Apache-2.0 backend you can audit and self-host.
• Native Better Auth, Next.js and Supabase SDKs — no other MoR ships these.
• Built-in license keys, GitHub repo access and Discord roles eliminate a second tool like LemonSqueezy + Whop.
• No monthly fee, no minimum, no per-seat — the cost is transparent and scales linearly with revenue.
• Backed by Accel ($10M seed) and an exceptional angel list including engineers from Vercel, Supabase, Shopify and Raycast — a real signal of staying power.

Cons:

• Effective rate can hit 6% + $0.40 once international and subscription surcharges stack — you must run the math for your actual mix, not the sticker.
• Support response times during disputes have been criticized in February 2026 Reddit threads — there's no SLA on free tiers.
• Stripe Connect Express payouts only cover ~120 countries — narrower than Paddle's 200+.
• Younger product than Paddle/LemonSqueezy — some enterprise compliance docs (SOC 2 Type II, etc.) are still being completed.

Alternatives to Polar

Lemon Squeezy is the closest competitor: also a Merchant of Record, also developer-friendly, but closed source and now owned by Stripe. Paddle covers more countries (~200) but its UI is dated and pricing is opaque. Stripe + Anrok is the build-it-yourself option — cheaper at scale but you remain the merchant of record and inherit all VAT liability. For pure open source, Listmonk-style self-hosting with raw Stripe is an option but you give up the MoR shield entirely.

Verdict: Is Polar Worth It?

If you ship a developer tool, AI agent, VS Code extension or a small SaaS and you want to stop wiring Stripe + Stripe Tax + license-key infrastructure by hand, Polar is the cleanest option in 2026 — and the only one whose code you can actually read. Just be honest about the real fee math: budget 5–6% of revenue, not 4%, and the choice becomes obvious. The 83/100 reflects a genuinely best-in-class developer experience held back from a higher score by the surcharge stack and the still-young support organization.

Frequently Asked Questions

Is Polar free?

There is no monthly fee or seat charge. Polar is free to set up and free to self-host (Apache-2.0); you only pay 4% + $0.40 per successful transaction on the cloud, with international and subscription surcharges that can bring the effective rate to ~6% + $0.40.

Is Polar.sh open source?

Yes. The full backend (FastAPI + Postgres) and frontend (Next.js) are under Apache License 2.0 at github.com/polarsource/polar. You can self-host the entire stack — though Polar Cloud is required to use Polar as the legal Merchant of Record.

Does Polar handle sales tax and VAT?

Yes. As Merchant of Record, Polar collects, files and remits VAT, US sales tax, GST, and EU OSS in 50+ jurisdictions automatically. You only see net payouts.

How does Polar compare to Lemon Squeezy?

Both are Merchant of Record platforms aimed at developers and indie SaaS. Polar is fully open source under Apache 2.0 and ships first-party Better Auth, Next.js and Supabase SDKs; Lemon Squeezy is closed source, Stripe-owned since 2024, and has broader merchant support but no public SDK story for modern auth frameworks.

What countries can receive payouts from Polar?

About 120 countries supported via Stripe Connect Express. Major markets in North America, EU, UK, Australia and most of Latin America and Asia-Pacific are covered; some African and Central Asian countries are not.

Does Polar work with Better Auth?

Yes — there is an official @polar-sh/better-auth plugin maintained by the Polar team. It auto-creates Polar customers from Better Auth signups, exposes a checkout helper, and provides a customer portal for subscription management.