When Polar makes sense
Polar is especially interesting for developer-focused products that want merchant-of-record operations without building payment infrastructure from scratch.
Provider comparison
Polar.sh Fee Calculator
Estimate Polar fees for developer tools, open-source products, and SaaS payments, then compare take-home revenue with other providers.
What to compare
Compare MoR fees against Stripe-style payment processing plus the extra work of tax, compliance, invoices, and global selling.
Polar fee assumptions
This page models Polar Starter as 5% + $0.50 per transaction, with international card and dispute assumptions handled separately in the main calculator.
Why Polar is different
Polar is developer-focused. It is worth comparing for open-source products, paid downloads, license keys, and SaaS products with a technical buyer.
Simple Polar example
On Polar Starter, a $50 transaction at 5% + $0.50 has an estimated base fee of $3.00 before international card extras or disputes. For technical products with global buyers, the international-card share is worth modeling explicitly.
Paid-plan break-even
Polar also lists paid plans with lower variable rates. Once monthly sales grow, compare Starter against Pro, Growth, and Scale because a fixed monthly fee can become cheaper than a higher percentage fee.
Best fit
Polar is a strong candidate for developer tools, open-source sponsorship-style products, paid downloads, licenses, API products, and small SaaS tools where the buyer is technical and the seller wants merchant-of-record coverage.
What to watch
The headline rate is only one part of the model. International cards, payouts, disputes, subscription fees on older plans, and paid-plan thresholds can all change the real net revenue.
Model the developer workflow
Polar should be judged on more than the fee line. For a developer tool, checkout may sit beside documentation, GitHub, license keys, downloads, private repositories, or API access. If the payment flow reduces manual access work, that operational gain belongs in the comparison.
Also check whether buyer emails, receipts, and access delivery match the support workflow your users expect. Small delivery gaps can create support cost. Model that support time beside the transaction fee.
Check the upgrade path
A small product can start on a simple plan, but the best provider should still work when revenue, support load, and customer geography change. Re-run the model at higher revenue levels and compare whether a paid Polar plan or another merchant-of-record option becomes cheaper at scale.
Run the numbers
The homepage calculator compares Polar with Stripe, Paddle, and Lemon Squeezy.
Open the calculatorUseful official sources
Polar Fee Calculator FAQ
Does Polar charge international card fees?
Polar's published pricing lists international card extras separately, so the calculator keeps that assumption visible instead of hiding it.
Should I model paid Polar plans?
Yes, once revenue grows. The current first version models Starter; paid-plan break-even comparisons are a good next feature.
Is Polar only for open-source projects?
No. Open-source products are a natural fit, but Polar can also be considered for developer-focused SaaS, downloads, licenses, and API products.
Why compare Polar with Paddle and Lemon Squeezy?
They can all be evaluated as merchant-of-record options. The right choice depends on product type, pricing model, buyer geography, and which workflow feels easiest to operate.