“Free” fundraising platforms almost always make money somewhere — through donor tips, processing markups, or premium upsells. Here is what to look for before you commit to any platform.
When a platform says it is free, that word does a lot of heavy lifting. It might mean no monthly subscription. It might mean donors cover costs instead of you. Or it might mean the free version is just a teaser for a much pricier plan. For nonprofits planning a Giving Day, the gap between what a platform advertises and what you actually keep can cost thousands of dollars.
This post breaks down how five platforms really make money — and which one actually delivers on its promises.
Quick Takeaways
- No fundraising platform operates for free. Someone always pays — you, your donors, or both.
- The advertised rate is rarely the effective rate once you factor in processing, tiers, and add-ons.
- A donor-covers-fees model can protect nonprofit revenue without pressuring donors — if it is built the right way.
- Mightycause’s Pricing Guarantee caps your aggregate processing fee at 1.99% + $0.49 per transaction, with an average effective rate of just 0.95%. Any overages are credited back to you before disbursement.
- Platforms with opaque or quote-based pricing make it hard to compare true costs before you sign.
The Platforms Compared
Mightycause
What It Advertises
Mightycause leads with a simple promise: $0/month subscription, lowest processing fee — period. It does not hide pricing behind a sales call. Every nonprofit sees the same rates. (Mightycause pricing)
How It Actually Makes Money
Mightycause charges an aggregate processing fee capped at 1.99% + $0.49 per transaction. That is the ceiling — most organizations pay even less. The platform’s average effective rate is just 0.95%, which is lower than what PayPal charges nonprofits for a basic donate button.
Here is how the donor-covers-fees model works: donors are offered a simple, optional checkbox to cover a 7.9% + $0.30 fee. If they say yes, you receive 100% of their gift. If aggregate fees across your account exceed 1.99% + $0.49, Mightycause credits the difference back to you before disbursement. That is the Pricing Guarantee, and it is the only one of its kind in the space. (See how it works)
There is no tip prompt. There is no pressure. Donors choose once, and the language is transparent.
Why It Works for Giving Days
Mightycause was built with community Giving Days in mind. It powers fully branded event websites, real-time leaderboards, peer-to-peer fundraising, and participant management — all under one roof. Community foundations and universities running multi-nonprofit Giving Days rely on it because the fee structure does not erode the grants and matches they work hard to secure.
Because Mightycause operates as a Donor Advised Fund (DAF), it also handles tax receipting and 501(c)(3) compliance for every donation processed. That is infrastructure most platforms charge extra for.
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Zeffy
What It Advertises
Zeffy calls itself the only 100% free fundraising platform for nonprofits. No platform fee, no transaction fee — none of it. Over 100,000 nonprofits use it as of 2026, and that growth is real. (Zeffy)
How It Actually Makes Money
Zeffy is funded entirely by optional donor contributions. When someone donates through a Zeffy form, a contribution to Zeffy is pre-selected in the checkout flow. The default percentage varies by transaction size and is set by an algorithm — nonprofits cannot customize or turn it off. Zeffy reports that the majority of donors leave a contribution, which covers Zeffy’s overhead and credit card processing costs.
This matters for two reasons.
First, the tip model shifts cost to donors rather than eliminating it. A donor making a $50 gift may see a 15% contribution pre-selected, meaning they are asked to pay $57.50. Some donors do not notice. Some feel pressured. And some feel misled when they check their bank statement. That friction can damage your donor relationships — not Zeffy’s.
Second, the model depends on donor behavior Zeffy cannot control. If contribution rates drop, the platform’s ability to cover credit card processing costs comes into question. Zeffy has acknowledged that in rare cases where a nonprofit raises large amounts with low contribution rates, it may reach out to discuss the arrangement.
For a one-time campaign, Zeffy can work well. For a Giving Day where donor trust and repeat giving matter, the model introduces uncertainty.
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Donorbox
What It Advertises
Donorbox markets itself as free to start — no setup fees, no monthly cost on the Standard plan. It highlights ease of use and the ability to let donors cover fees at checkout.
How It Actually Makes Money
The free Standard plan comes with a 2.95% to 3.95% platform fee on every transaction, depending on which feature you use. That is before payment processing.
On top of the Donorbox fee, you owe Stripe or PayPal their cut. With Stripe’s nonprofit rate at 2.2% + $0.30 and Donorbox’s base fee at 2.95%, a $100 donation on the Standard plan could cost you more than 5% in combined fees.
To lower fees, you need to upgrade. The Pro plan is $139 per month (as of 2026) and brings platform fees down to 1.75% to 2%. The Premium plan requires a custom quote. Popular add-ons — like Text-to-Give, API access, and CRM integrations — layer on quickly. A free Donorbox setup can become a $300+ monthly expense before you have even launched a Giving Day.
The donor-covers-fees option is available, but the amount donors are asked to cover includes both the Donorbox fee and an estimated processor rate. If your actual rate differs, nonprofits may absorb the gap.
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Funraise
What It Advertises
Funraise leads with a free Essentials tier and premium plans at higher volumes. It emphasizes its donor-covers-fees model and reports that about 90% of donors choose to cover fees. (Funraise Payments)
How It Actually Makes Money
Funraise’s fee model works differently than most platforms. On the free Essentials tier, Funraise does not charge a flat platform fee to the nonprofit. Instead, a platform fee is only applied when a donor opts to cover fees at checkout. If a donor does not cover fees, the nonprofit pays only the payment processing fee of 2.9% + $0.60 via Funraise Payments (powered by Stripe). (Funraise Payments details)
That means your baseline cost without donor coverage is the card processing rate — not a stacked combination of platform and processor fees.
When donors do cover fees — which Funraise says happens about 90% of the time — the average effective rate drops to approximately 0.8% on premium plans. Those are solid numbers, but they depend on donors saying yes at checkout consistently.
Key features like peer-to-peer fundraising, SMS messaging, auctions, and advanced reporting are locked behind paid plans. For a Giving Day that relies on team fundraising and real-time leaderboards, that means you are likely paying from day one. Premium pricing is quote-based, which makes it hard to budget without getting on a call.
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OneCause
What It Advertises
OneCause positions itself as an all-in-one event and auction platform. It offers a Pay-As-You-Go plan and highlights its award-winning support team.
How It Actually Makes Money
OneCause’s Pay-As-You-Go plan charges a 5% fee on funds raised, with a cap. For organizations raising under $50,000 annually, this can work. But a nonprofit raising $200,000 at a Giving Day event could owe up to $10,000 under this model before hitting the cap.
For organizations with higher volumes, OneCause moves to annual subscription pricing. The Professional package starts at $2,995 per year. Enterprise and Nationals tiers require custom quotes. None of the higher tiers show pricing publicly, which means every buying conversation starts with a sales call.
OneCause is a strong product for gala-style events and live auctions. But for nonprofits that want transparent pricing and a platform built for Giving Days — with community foundation tools, multi-org support, and a no-subscription model — the cost structure and sales process add friction that smaller organizations should weigh carefully.
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True Effective Rate Comparison
| Platform | Monthly Cost | Platform Fee | Processing Fee | Avg. Effective Rate |
| Mightycause | $0 | Capped at 1.99% + $0.49 aggregate | Included in cap | ~0.95% (with donor coverage) |
| Zeffy | $0 | $0 to nonprofit | Covered by Zeffy via donor tips | 0% to nonprofit; donor pays optional tip |
| Donorbox | $0–$139+/mo | 1.75%–3.95% | 2.2% + $0.30 (Stripe nonprofit rate) | ~5%+ on free plan |
| Funraise | $0 (Essentials) | $0 if donor doesn’t cover | 2.9% + $0.60 | 2.9% + $0.60 without coverage; ~0.8% with 90% donor coverage |
| OneCause | $0 PAYG / $2,995+/yr | 5% PAYG (capped) | Varies by processor | ~5% PAYG; lower on annual plans (quote required) |
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How to Calculate the True Cost of a Platform
Before you sign up for any fundraising platform, ask these four questions:
1. What is the combined fee per transaction?
Add the platform fee and the payment processing fee together. A 2% platform fee plus a 2.2% + $0.30 processing fee (Stripe nonprofit rate) means roughly 4.2% on a $100 gift.
2. Is there a monthly subscription?
A $139/month plan costs $1,668 per year. If you raise $50,000 annually, that is 3.3% of your revenue before you process a single donation.
3. What features require a paid upgrade?
Peer-to-peer fundraising, CRM integrations, and analytics are often locked behind higher tiers. Know what you need before you see the base price.
4. Who pays if donors decline to cover fees?
On some platforms, you absorb the full cost if donors say no. On Mightycause, the Pricing Guarantee ensures you never pay more than 1.99% + $0.49 in aggregate processing fees per transaction — no matter what. (Details)
A real example: Say you raise $100,000 on a Giving Day. At Mightycause’s 0.95% average effective rate, you keep $99,050. At a platform charging 5% plus a $139/month subscription, you keep roughly $93,332. That is nearly $5,7ssion funding — enough to fund a full program for many nonprofits.
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Ready to See the Difference?
Mightycause’s Giving Day platform is built to protect your revenue, not erode it. With a $0 subscription, a capped processing fee, and transparent donor-covers-fees tools, your team can focus on community — not cost math.
Request a Giving Day demo with Mightycause and see why over 76,000 nonprofits trust us with their fundraising (as of 2026)
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Frequently Asked Questions
Is Zeffy really free for nonprofits?
Zeffy charges nonprofits no platform or transaction fees, but it is funded by optional donor contributions that are pre-selected in the checkout flow — so someone still pays, just not the nonprofit directly.
What is a donor-covers-fees model?
A donor-covers-fees model lets donors opt in at checkout to add a small amount that covers the platform’s processing costs, so the nonprofit receives 100% of the intended gift.
How do I calculate the true cost of a fundraising platform?
Add the platform fee, payment processing fee, and any monthly subscription together, then model it against your expected fundraising volume to find your true effective rate.