Polar is the newest serious merchant-of-record in the category and the only one built around modern usage-based billing as a first-class primitive, token metering, API call counting, GPU compute units, prepaid credits, the whole AI-product billing surface. 4% + 40c per transaction with no monthly fee, open source under Apache 2.0, and used by Vercel and Ghostty. Newer means smaller ecosystem and fewer integrations than Stripe or Paddle, but for AI / dev product founders, Polar is the right shape.
- Merchant of record, global tax handled at 4% + 40c per transaction
- First-class usage-based billing, token metering, API calls, GPU units
- Prepaid credits, seat pricing, subscriptions, one-time all native
- Open source under Apache 2.0, credible self-hosting path
- No monthly fee, no setup fee, just per-transaction
- Newer than Stripe / Paddle, smaller integration ecosystem
- Documentation depth trails the incumbents
- Less battle-tested at high scale ($1M+ MRR)
- Fewer war-stories and community recipes than Stripe
- Focus on AI/dev means general-purpose features are thinner
Polar is a modern merchant-of-record platform built from the ground up for AI and developer products. Where Stripe is the general-purpose payments rails and Lemon Squeezy is the indie MoR for digital products, Polar is specifically shaped for the emerging class of products that bill per token, per API call, or per compute unit, usage-based billing is first-class, not bolted on.
Where it fits
Polar is the right pick for AI product founders selling LLM API access, agent platforms, GPU compute, or any product where the unit of value is metered rather than per-month. Token metering is a primitive, not a custom integration. Prepaid credits work out of the box. The merchant-of-record model means tax compliance is handled globally without needing a separate Stripe Tax integration.
For indie founders shipping non-AI products, Polar still works fine and the 4% + 40c is slightly cheaper than Lemon Squeezy’s 5% + 50c. The open-source Apache 2.0 license is the long-term escape hatch, production self-hosting is documented.
For high-scale SaaS, mid-market enterprise, or products needing the deepest API customization, Stripe + Stripe Tax + Stripe Billing typically wins on depth and ecosystem maturity.
Pricing in practice
4% + 40¢ per transaction covers everything, payments processing, global tax handling, dunning, subscription management, usage metering. No monthly fee, no setup fee. Compared to Stripe’s 2.9% + 30c (plus Stripe Tax at 0.5%, plus operational tax cost), Polar nets out cheaper for most indie and small-team scenarios once compliance overhead is factored in.
Higher-volume merchants can negotiate custom rates, and the Apache 2.0 license means self-hosting is a real cost lever for teams at scale willing to operate the infrastructure.
How it compares
Stripe, Deepest payments API surface, you handle tax separately. Pick for general-purpose programmability and at scale.
Lemon Squeezy, Older indie-friendly MoR optimized for digital downloads. Pick for one-time digital products with license key delivery.
Paddle, Mid-market SaaS MoR with ProfitWell analytics. Pick at mid-market scale where dunning and analytics matter most.
What changed recently
Polar has shipped aggressively through 2025-2026 with token metering, GPU compute billing, prepaid credit systems, and seat-based pricing as first-class primitives. The platform’s positioning as “billing for AI / dev products” has sharpened with usage-billing patterns specifically called out for LLM APIs and agent platforms. Vercel and Ghostty have publicly adopted Polar, validating the production readiness of the platform. The Apache 2.0 self-hosted path has matured into a credible production option.
Sources
- Polar, polar.sh
- Polar Docs, polar.sh
- Polar GitHub, github.com
- Polar Usage-Based Billing, polar.sh