PDF Generator API alternative: per-document plans, no editor required
PDF Generator API is a template-platform veteran: a document editor, workspaces, form filling, QR codes, even an eInvoice API, all behind credit-based plans. If your product needs user-designed documents, that machinery earns its price. If you need invoices and receipts out of an API, most of it is weight you carry without using. Here is the honest breakdown.
Side by side, as of June 2026
Pricing and features below were checked against pdfgeneratorapi.com/pricing in June 2026 (annual prices shown there; monthly billing costs about 17% more). Always confirm current numbers on their site.
| PDF Generator API | Slipstack | |
|---|---|---|
| Approach | Document template editor + HTML-to-PDF, JSON data merged into templates | JSON only, built-in invoice and receipt layouts |
| Free option | 14-day trial; unlimited test documents; no permanent free plan listed | Free forever: 50 documents/month, no card |
| Billing unit | Credits: 1 credit per 5-page block | Documents: one render, one document |
| Entry plan | Creator: 80 euros/yr for 50 credits/mo, 5 templates | Starter: $19/mo for 1,000 documents |
| Mid plan | Basic: 880 euros/yr for 5,000 credits/mo | Pro: $49/mo for 5,000 documents |
| Rate limits | 30 to 240 requests/minute, by plan | Plans tier on monthly document quota |
| Embeddable editor for your SaaS | Yes, on higher tiers | No |
| Form filling, QR codes | Yes | No |
| EN 16931 e-invoicing (Factur-X, XRechnung) | Yes, eInvoice API | Yes: CII XML + Factur-X hybrid PDF on Pro, parsing on Starter |
| Totals, tax, discounts | Computed in your template or payload | Computed by the API from line items |
| Agent integration | None documented | Remote MCP server at /api/mcp |
When PDF Generator API is the better choice
- Your users design their own documents. The embeddable template editor lets your SaaS customers build layouts inside your product. Slipstack has nothing comparable.
- You need PDF form filling or QR codes. Those workflow features go beyond pure generation, and Slipstack does not offer them. (E-invoicing is no longer a gap: Slipstack generates EN 16931 CII XML and Factur-X hybrid PDFs on the Pro plan.)
- Many document types, one vendor. Delivery notes, labels, contracts, and invoices from the same template system and the same credits pool.
- Certifications matter. As of June 2026 they list ISO 27001 certification and HIPAA and GDPR compliance across plans.
When Slipstack fits better
- You want to start free, not on a trial clock. Slipstack's 50 documents/month tier never expires. As of June 2026, PDF Generator API's entry point after the 14-day trial is the Creator plan at 80 euros/year for 50 credits a month.
- Documents, not credits. An invoice is one document, full stop. No mental arithmetic about page blocks, no surprise at a 6-page statement costing double.
- No template editor to learn. The layout is built in. Send
logoUrlandaccentColorfor branding, and the API computes subtotals, discounts, and tax from your line items. - Agents can call it natively. The Slipstack MCP server exposes invoice and receipt generation as tools for Claude and any MCP client. Setup takes one line; see the AI agents guide.
FAQ
How does PDF Generator API's credit pricing work?
As of June 2026, every document is billed in blocks of 5 pages: a 1-5 page document costs 1 credit, 6-10 pages costs 2 credits, and so on. Annual plans run from the Creator tier at 80 euros/year (50 credits/month, 5 templates) to Enterprise at 6,208 euros/year (250,000 credits/month). Slipstack bills per document regardless of typical invoice length: $19/month for 1,000 documents, $49 for 5,000, $199 for 50,000.
Does PDF Generator API have a free plan?
As of June 2026 their pricing page lists a 14-day free trial with sandbox access, not a permanent free plan, though test documents are unlimited on all plans. Slipstack has a free-forever tier: 50 documents per month, live and test keys, no card required.
Do I need to build templates with Slipstack?
No. PDF Generator API is built around its document template editor, which is powerful if you need it and overhead if you do not. Slipstack ships finished invoice and receipt layouts; you send JSON with line items and branding, and the API computes totals and renders the PDF.
Can my customers design their own documents in Slipstack?
No. PDF Generator API offers an embeddable template editor so your SaaS users can design their own document layouts, which Slipstack has no equivalent for. If user-designed templates are a product requirement, choose PDF Generator API.
Which one is agent-ready?
Slipstack runs a remote MCP server at slipstack.dev/api/mcp, so Claude, Claude Code, Cursor, and any MCP client can generate invoices as a native tool with a no-signup demo quota. PDF Generator API does not document an MCP integration as of June 2026.
One document, one API call, no credits
Free tier: 50 documents a month, no card, no trial expiry. Test the layout in your browser.
Related reading
- Anvil alternative for another metered-pricing comparison.
- Carbone alternative if your templates should live in Word or Excel.
- Add PDF invoices to your app in 5 minutes with code examples.