Polar is an open-source billing platform and merchant of record for digital products and SaaS businesses, aimed at developers and AI startups that charge for tokens, API calls, and subscriptions. It combines event-level usage metering, subscriptions, prepaid credits, and hosted checkout with worldwide VAT, GST, and sales-tax handling, so sellers offload tax compliance, receipts, and payouts to Polar.[1][2]
Quick verdict
AI startups and developers selling digital products globally will get the most from Polar, especially when usage-based pricing and tax compliance must work out of the box. Its open-source platform meters tokens, agent runs, and compute down to the event and bills through subscriptions, credits, or one-time purchases with Polar settling money as merchant of record. The price of that convenience is platform dependence: tax collection and payouts run through Polar's hosted service with per-transaction fees, and no production self-hosting path is documented. If you want open-source billing with merchant-of-record tax handled for you, choose Polar; if billing data must stay self-hosted, evaluate the published incumbent Lago first.[1][2][3]
Key features
Event-level usage metering: bill tokens, API calls, agent runs, GPU seconds, and storage from event streams aggregated into live per-customer meters.[1]
Subscriptions with trials and proration: recurring plans with upgrades alongside one-time purchases and pay-what-you-want products.[1]
Prepaid credits: balances that draw down as customers consume usage and top up automatically.[1]
Merchant-of-record tax handling: Polar calculates, collects, and remits VAT, GST, and sales tax worldwide.[1]
Hosted checkout and customer portals: localized currencies, receipts, dunning management, and scheduled payouts.[1][2]
Automated benefit delivery: license keys, file downloads, GitHub repository access, and Discord roles granted on purchase.[1]
Public REST API with webhooks plus official JavaScript and Python SDKs: define products and send events from code with framework adapters for fast integration.[1]
Transparent transaction pricing: Starter free at 5% + $0.50 per transaction, Pro 3.8% + $0.40, Growth 3.6% + $0.35, Scale 3.4% + $0.30.[1][2]
Who will love it
AI startups billing tokens, agents, or compute: per-event metering and credit billing match consumption pricing directly.[1][2]
Developers selling digital products worldwide: merchant-of-record status removes VAT, GST, and sales-tax paperwork.[1]
Small teams without billing infrastructure: checkout, portals, dunning, and payouts arrive as one integration.[1][2]
Who should avoid it
Teams that must self-host billing data: no production self-hosting path is documented and settlement runs through Polar's hosted service.[1][2]
Buyers avoiding per-transaction fees: every plan takes a percentage plus a fixed fee on each transaction.[1][2]
Teams needing confirmed SSO, offline use, or data-region guarantees: none of these were documented in the sources reviewed.[1][2][3]
Alternatives and compatibility
Lago is the published catalogue incumbent; the choice turns on Polar's merchant-of-record settlement and tax handling versus Lago's self-hosted, processor-orchestrated billing scope, with full incumbent comparison pending its own evidence.[1][2]
Portability facts: the repository is Apache-2.0, the stack is Python-led with TypeScript, and billing runs through Polar's hosted checkout, API, and SDKs.[1][2][3]
If you need open-source billing where usage metering, subscriptions, and global tax are handled by your merchant of record, choose Polar; if you must run the billing ledger in your own infrastructure, evaluate the incumbent first.[1][2]
Questions worth asking
What is the best Polar alternative for non-technical users?
Is Polar really no-code?
No for everyday setup: Polar integrates through its public API, webhooks, SDKs, and framework adapters, so defining products and sending usage events needs developer work. Non-technical staff can use the resulting hosted checkout, customer portals, and payouts once developers have wired it up.[1][2]
How much does Polar cost per month?
There is no monthly fee: the Starter plan is free at 5% + $0.50 per transaction, Pro is 3.8% + $0.40, Growth is 3.6% + $0.35, and Scale is 3.4% + $0.30, with additional fees possible. Eligible startups can apply to the Startup Program for a year on the most generous plan. Prices checked October 12, 2026.[1][2]
Sources and editorial review
Source research. Reviewed on October 12, 2026. Written by Sanjib Sah. AI assisted; reviewed by a human editor.
We have not run or tested this product.
- Polar official site
official · Observed October 12, 2026
Official homepage: billing platform for the intelligence era; usage billing, subscriptions, credits as composable primitives; token/API/GPU metering; hosted checkout; payouts; merchant of record; Startup Program.
- Polar docs introduction
official · Observed October 12, 2026
Official docs introduction: merchant-of-record tax compliance, billing infrastructure vs transaction-only processors, automated benefit delivery, product and pricing shapes, Starter fee 5% + $0.50.
- Polar repository (official)
official · Observed October 12, 2026
Official repository: canonical identity polarsource/polar; billing platform for the intelligence era.
- Polar LICENSE (Apache-2.0)
official · Observed October 12, 2026
Repository LICENSE file: full Apache License Version 2.0 text.
- Polar README (official repository)
official · Observed October 12, 2026
Repository README: AI-workload metering, merchant of record, four pricing tiers, Public and Webhook APIs, JS/Python SDKs, private security disclosure.
- Polar language statistics
official · Observed October 12, 2026
GitHub language statistics: Python largest share, TypeScript second, Dockerfile markers present.
Compared with these products
No explicit proprietary baseline is recorded.