Comparison
Doc2api vs Formstack Documents
No longer sold on its own — a different kind of purchase from an API, and priced accordingly.
Where Formstack Documents is the better choice
Genuinely — if any of these is your requirement, stop reading and use them.
- A whole suite — forms, documents and e-signature from one vendor with one invoice and one support contract, which is exactly what some procurement departments want.
- A HIPAA-compliant path exists — their page shows PCI/HIPAA as an add-on to Forms and Suite, and as part of Enterprise. Doc2api makes no HIPAA claim at all, so if you are handling US health data under a BAA that settles it in their favour.
- Unlimited e-signatures on the Suite plan, as a first-class product rather than a signature image stamped into a PDF.
- A long-established company, which for some buyers is the point.
What Doc2api does
Three jobs, one endpoint — worth knowing before the comparison below.
1
Fill a PDF you were given
Upload a fillable PDF and its fields come back as a typed JSON schema. Flat or scanned, you draw named boxes on the page instead. The output is that exact document.
2
Design one from nothing
A drag-and-drop designer: tables with repeating rows, bar/line/pie charts, barcodes and QR codes, signature blocks, running headers and footers, watermarks, page numbers, a brand colour and type scale, elements that appear only when an expression is true, and six page sizes from A5 to Tabloid. No markup required.
3
Or hand us your own HTML
An HTML block takes your markup — headings, tables, lists, images, links and inline styles — and renders it into the document, script-free and parsed against an allow-list. Paste what you already generate instead of rebuilding it.
Where Doc2api differs
You cannot get an API at their published price
Formstack's pricing page lists “API Access and custom integrations” among the Enterprise features, not the Suite. So the thing a developer came for is not on the published $250-a-month plan at all — it needs a sales conversation and a custom quote. Doc2api’s API is the product, on every plan, including free.
You can buy just the piece you need
If all you want is an endpoint that returns a filled PDF, that starts at $20 a month here. The Suite is $250 a month billed annually and includes a forms product and an e-signature product you may have no use for.
An API first, with a designer when you want one
Doc2api is documented for developers — signed webhooks, per-audience field rules, one endpoint per document — but it also has a visual designer and an HTML block, so a colleague can change the document without anyone writing code. You are not choosing between a platform and an API.
You can see it working in two minutes
No sales conversation, no annual commitment, no account. Upload the PDF and read the JSON schema that comes back.
Published pricing
Formstack Documents's figures read from their pricing page on 7 August 2026. They may have changed since — check before deciding, and email support@doc2api.co if anything here is out of date.
Formstack Documents
| Plan | Price | Included |
|---|---|---|
| Suite | $250/mo billed annually ($299 monthly) | Unlimited Document senders and unlimited eSignatures; merge volume not published |
| Enterprise | Custom | Includes HIPAA-compliant options |
Doc2api
| Plan | Price | Per 1,000 docs |
|---|---|---|
| Free | $0 | 50/mo, no expiry |
| Starter | $20/mo1,000 documents/month | $20.00 |
| Pro | $50/mo10,000 documents/month | $5.00 |
| Business | $200/mo100,000 documents/month | $2.00 |
| Business + 500,000 documents pack | $1,000/mo600,000 documents/month | $1.67 |
Reading these tables: Formstack's pricing page does not break Documents out on its own — it appears only as part of the Suite, and does not state a document-merge allowance. That means a cost-per-document comparison is not possible here, and we are not going to estimate one. Third-party sites still quote older standalone tiers; those did not match Formstack's own page when we last read it. Their 14-day trial covers the core Forms product.
Cost per document is not the whole comparison — and it does not always favour us. Where it does, it still ignores everything in the section above; where it does not, we have said so there. Read both.
Choose Formstack Documents if…
You want forms, documents and e-signature from one vendor, you need HIPAA coverage, or an annual suite contract is how your organisation prefers to buy.
Choose Doc2api if…
You want one endpoint that fills a PDF, priced monthly, that you can try today without talking to anyone.
Decide it in two minutes instead
Upload the actual PDF you need filled and see what comes back. You get a working endpoint and a real API key — no account, nothing to cancel.