Sirnia is a free Formstack alternative with unlimited forms and unlimited responses. Formstack has no free plan and starts at $83/month for a single user.
Where Formstack's cheapest plan caps you at 25 forms and 1,000 submissions per form for $83–99/month, Sirnia includes conditional logic, calculated fields, file uploads, and payment processing on the free plan, with no submission cap. Sirnia's editor works like a document, just start typing to build your form, no drag-and-drop required.
Users rate Sirnia 4.9/5 on G2 (471+ reviews put Formstack at 4.3/5), with reviewers frequently citing Formstack's pricing as a pain point.
Feature comparison: Sirnia vs Formstack
Feature | Sirnia | Formstack |
Free plan | ✅ Unlimited forms & responses | ❌ No free plan (14-day trial only) |
Unlimited forms | ✅ Free | ❌ 25 forms on Forms plan ($83+/mo); 100 on Suite ($250+/mo) |
Unlimited responses | ✅ Free | ❌ 1,000 submissions/form ($83+/mo); 5,000 on Suite ($250+/mo) |
Users included | ✅ $29/mo (unlimited users) | ❌ 1 user (Forms, $83+/mo);
3 users (Suite, $250+/mo) |
Multi-page forms | ✅ Free | ✅ $83+/mo |
Conditional logic | ✅ Free | ✅ $83+/mo |
Calculated fields | ✅ Free | ✅ $83+/mo |
File uploads | ✅ Free (10MB/file) | ✅ $83+/mo (2GB total storage) |
Accept payments | ✅ Free | ✅ $83+/mo |
Export submissions as PDF | ✅ Free | ⚠️ Not native — handled by the separate Formstack Documents product |
Templated document generation | ❌ Not available | ✅ $250+/mo |
E-signatures | ✅ Free | ✅ $250+/mo |
Custom domains | ✅ $29/mo | ✅ Included |
Custom CSS | ✅ $29/mo | ✅ Included |
Webhooks | ✅ Free | ✅ Included |
API access | ✅ Free | ❌ Enterprise plan (custom pricing) |
Salesforce integration | ❌ Not available | ✅ Solutions plan (custom pricing) |
Approval workflows | ❌ Not available | ✅ $250+/mo |
SSO | ❌ Not available | ✅ Enterprise (custom pricing) |
HIPAA-compliant forms | ❌ Not available | ✅ Salesforce plan (custom pricing) |
AI form builder | ✅ Free | ❌ Not available |
MCP server (AI agent access) | ✅ Free | ❌ Not available |
Import forms | ✅ Free | ❌ Not available |
Sirnia vs Formstack: which should you pick?
Formstack is built for teams that need forms bundled with document generation, eSignatures, and Salesforce workflows — and it prices accordingly, with no free tier and a $83+/month entry point. Sirnia is built for anyone who wants a fully-featured form builder without the enterprise price tag: unlimited forms and responses, free, for solo builders, startups, and growing teams alike.
If your team already lives in Salesforce and needs native document workflows, Formstack's higher tiers are built for that. If you want to get a professional form live today without committing to a monthly fee, Sirnia is the more practical starting point.
Where Sirnia wins
Sirnia's free plan removes the paywalls that Formstack puts up from day one:
- No submission cap, ever. Formstack's Forms plan — its cheapest paid option at $83–99/month — still caps you at 1,000 submissions per form. Sirnia has no cap, and offers unlimited forms and submissions free.
- No per-seat pricing to start. Formstack's Forms plan includes exactly one builder user; adding teammates means jumping to the $250–299/month Suite plan. Sirnia Pro ($29/mo) adds unlimited team workspaces.
- A document-style editor. Type
/to insert a question, drag to reorder — no separate drag-and-drop canvas to learn.
- AI-ready by design. Sirnia AI helps you build and edit forms in plain language, and a free MCP server connects your forms to AI assistants like ChatGPT and Claude. Formstack offers neither.
- Import your existing forms. Upload a PDF, screenshot, Word, CSV, JSON, or Markdown file and Sirnia rebuilds it as an editable draft — so leaving Formstack doesn't mean starting from scratch.
- Beautiful forms, advanced customization. Sirnia forms look polished out of the box, and it's easy to make them match your brand with layouts, cover images, and themes — with custom CSS and custom domains on Sirnia Pro for full design control.
- Fast, human support. Sirnia is run by a small team that takes pride in answering support questions within 2 hours — no ticket queues or chatbot loops.
Where Formstack wins
To be fair, Formstack has real advantages for larger, more regulated teams:
- Templated document generation and signature routing in one product. Formstack Suite bundles templated document creation and multi-party eSignature routing alongside forms. Sirnia captures electronic signatures for free and exports every signed submission as a PDF, but it doesn't generate templated documents or route them to multiple signers.
- A dedicated Salesforce integration. Formstack's Salesforce Solutions plan includes native Salesforce forms and Experience Cloud integration. Sirnia has no native Salesforce connector today.
- HIPAA-compliant forms. Formstack has a dedicated healthcare offering for HIPAA-compliant data collection. Sirnia does not currently offer this.
- Enterprise-grade approval workflows and support. Formstack's Suite and Enterprise tiers include multi-step approval routing, SSO, and a dedicated customer success manager — better suited to large organizations with procurement and compliance requirements than Sirnia's self-serve model.
If any of these are must-haves for your team, Formstack is worth the higher price.
Who should choose which?
- Solo builders, freelancers, and startups — choose Sirnia. Formstack's $83+/month entry price and 1-user cap make it impractical before you have real budget for it.
- Small teams that just need forms, payments, and file uploads — choose Sirnia. Everything is free, with no submission limit.
- Healthcare teams that need HIPAA-compliant intake forms — choose Formstack.
- Sales or ops teams already running on Salesforce who need forms to write directly into it — choose Formstack's Salesforce Solutions plan.
- Teams that need document generation and eSignature routing alongside forms — choose Formstack Suite.
- Larger orgs that need SSO, approval workflows, and a dedicated success manager — choose Formstack Enterprise.
Migrating from Formstack to Sirnia
Sirnia doesn't have a one-click Formstack importer today But Sirnia's file import is deliberately broad: it accepts PDFs, images or screenshots, JSON, CSV, Markdown, and Word files, and turns any of them into an editable draft form.
In practice, migrating a Formstack form to Sirnia looks like this:
- Open your Formstack form and either print it to PDF (File → Print → Save as PDF) or take a screenshot of each page.
- In Sirnia, click
New form → Import from, and upload the PDF or screenshot.
- Sirnia rebuilds the questions as an editable draft form. Review it, then add back conditional logic, calculated fields, or payment blocks, since logic and calculations aren't extracted automatically from a flat PDF or image.
If you'd rather skip the file altogether, Sirnia AI can rebuild the form from a plain-language description, or from a screenshot or PDF pasted directly into the chat — logic, structure, and branding included, in a couple of minutes.
Frequently asked questions
Is Sirnia really free?
Yes. Sirnia's free plan includes unlimited forms and unlimited responses, with no credit card required. Formstack has no equivalent free plan, only a 14-day trial.
Can I create Sirnia forms that look like Formstack forms?
Yes. Sirnia supports single-page, multi-page, and mixed layouts, plus custom CSS on Sirnia Pro for full design control.
Can I migrate from Formstack to Sirnia?
Yes. Use Sirnia's import function to upload a PDF or screenshot of your Formstack form, and Sirnia rebuilds it as an editable draft. Sirnia AI can also recreate your form from a pasted screenshot or a plain-language description in a couple of minutes.
Does Sirnia integrate with Salesforce?
Not natively today. Formstack's Salesforce Solutions plan offers native Salesforce forms and Experience Cloud integration; Sirnia connects to Salesforce indirectly through Zapier or Make.
Why is Formstack so much more expensive than Sirnia?
Formstack prices for teams that need document generation, eSignatures, and Salesforce workflows bundled in, which is reflected in its $83–299/month tiers. If you just need a form builder, Sirnia covers the same core functionality (and more) for free. Sirnia can afford to do this because it's bootstrapped and customer-funded (no venture capital to repay) so the free plan is a sustainable part of the business, not a temporary promotion.
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