Pricing
Free to export. Pro for AI and unlimited everything.
The editor and every export format are free forever — no watermark, no signup. Pro adds a monthly AI allowance, all premium themes, and an unlimited cloud library. Credit packs top you up once, without a subscription.
- ✓ PNG, SVG, JPG, WebP, and PDF export
- ✓ No watermark, no signup required
- ✓ 1x / 2x / 4x scale and transparent backgrounds
- ✓ 3 standard export themes
- ✓ 10 free AI credits after sign-in
- ✓ 3 saved cloud diagrams
- ✓ Your diagram code stays in your browser
- ✦ Everything in Free
- ✦ 200 AI credits every month
- ✦ Unlimited premium theme exports — all 7 Advanced styles
- ✦ Unlimited cloud diagrams
- ✦ Every AI tool: text, screenshots, AI edits, interactive maps, syntax fixes
- ✦ Cancel anytime
What each plan includes
| Feature | Free | Pro — $5.99/mo | Credit pack |
|---|---|---|---|
| Export PNG / SVG / JPG / WebP / PDF | Unlimited, no watermark | Unlimited, no watermark | — |
| Export scale | 1x / 2x / 4x | 1x / 2x / 4x | — |
| Standard themes (3) | Included | Included | — |
| Premium themes (7 Advanced styles) | 2 credits per export | Unlimited | Or 2 credits per export |
| AI generate / edit / image to Mermaid | 10 free credits, once | 200 credits every month | 3 credits per use |
| Interactive system maps | From free credits | Included in monthly credits | 5 credits each |
| AI syntax fix | From free credits | Included in monthly credits | 1 credit |
| Cloud diagram library | 3 diagrams | Unlimited | — |
| Expires | Never — credits don't expire | Monthly allowance resets each month | Never |
Credits are the same currency everywhere: sign-in grants, Pro monthly allowance, and purchased packs all draw from one balance.
You get 20 credits for every friend who signs in; they get 5 bonus credits too.
Billing questions
Can I cancel Pro anytime?+
Yes. Cancel from your account page or PayPal in a few clicks. You keep Pro access until the end of the period you already paid for, then the account returns to the free plan — the editor and all export formats stay free either way.
How do AI credits work?+
Every signed-in account gets 10 free credits once. Pro adds 200 credits per month. Credits pay for AI actions as you use them: 3 for generating, editing, or converting an image, 5 for an interactive map, 1 for a syntax fix, and 2 for exporting a premium theme without Pro. Unused monthly credits reset at the start of each billing month; purchased credits never expire.
Do purchased credits expire?+
No. One-time credit packs never expire and work on both the free and Pro plans — on Pro they are only spent after the 200 monthly credits run out.
What payment methods do you accept?+
Payments go through PayPal — you can check out with a PayPal account or, where available, a card via PayPal guest checkout. The subscription and the credit packs are separate one-click purchases with no hidden renewals (only Pro renews, monthly, until you cancel).
Do I need an account to export?+
No. The editor, preview, and every export format work without signing in and without a watermark. An account is only needed for AI features, the cloud library, and purchasing.
What is your refund policy?+
If something you paid for did not work as described, write to hello@mermaidonline.org within 14 days and you will get a refund — no interrogation. Refunded packs remove the credits they added (a partially spent pack simply floors your balance at zero).