PDF form filling API, made simple.
Upload a template, let AI map the fields, hit the API. SimplyFill turns the data your app already has into perfectly-filled PDFs — onboarding docs, tax forms, contracts, healthcare paperwork — in one call.
// 1. Your app already has the data const applicant = { fullName: "Erick Ramirez", socialSecurityNumber: "***-**-1234", dateOfBirth: "1990-04-12", } // 2. POST to your template + mapping const res = await fetch("/api/v1/generate/pdf", { method: "POST", headers: { "Authorization": `Bearer ${apiKey}` }, body: JSON.stringify({ template_id: 42, mapping_id: 7, data: applicant, }), }) // 3. Response — grab the download_url { "status": "success", "file_id": "a3f2…b91", "download_url": "/api/v1/generate/download/a3f2…b91", "expires_at": "2026-05-23T17:01:00Z", "fields_filled": 3, "generation_time_seconds": 0.42 }
Three steps to your first filled PDF
No more hand-mapping cryptic AcroForm field names. Upload a template and AI reads its labels for you — suggesting names, mappings, and test data you approve in a click. Then fill it from your app’s data on every API call.
AI does the understanding. You do the deciding.
Real PDFs expose fields with meaningless names like f1_03[0]. SimplyFill’s wizard reads the visible labels and surrounding context the way a person would — and turns the form into a clean, mapped template in minutes. Every suggestion is yours to accept, edit, or reject.
Text1297invoiceNumberWhy: nearby label “Invoice #”
f1_07[0]91lineItem2QuantityWhy: table header “Qty”, row 2 · context: invoice
DateField395dueDateWhy: tooltip “Payment due date”
AI field aliasing
Turns gibberish like f1_03[0] into “Invoice Number” by reading the visible labels and surrounding context the way a person would — not the machine name.
AI field mapping
Connects each labeled field to your data schema automatically, and only proposes a match when it’s confident rather than guessing wrong.
AI field-type detection
Recognizes SSNs, EINs, emails, phone numbers, dates, currency, signatures, and more — so values are validated and formatted correctly downstream.
AI test-data generation
Fills a live preview with realistic, correctly formatted sample data — valid SSNs, ISO dates, consistent city/state/ZIP — so you confirm the form without touching real PII.
Confidence + evidence on every field
A 0–100 score and a short note (“tooltip”, “nearby label”) let you verify fast and spend time only on the uncertain ones.
You stay in control
Nothing publishes on its own. Accept, edit, or reject each suggestion — it’s AI-assisted setup, not automation you can’t see into.
Generation stays deterministic
AI only accelerates setup. The engine that fills your PDFs is predictable — same data in, same PDF out, no model in the hot path.
Built for production PDF workflows
Every feature you'd expect from a serious API platform — versioning, async, webhooks, bulk, environments — all wired into the same simple three-step workflow.
AI field aliasing
AI reads the visible labels to turn cryptic AcroForm names into clean aliases — each with a confidence score you approve. Your app sends fullName, not topmostSubform[0].Page1[0].f1_02[0].
Template versioning
Promote templates through dev → staging → production environments. Pin a specific version per API key so deploys never break filling.
Sync & async modes
Get the PDF back in the response for fast requests, or queue with async_mode: true for large batches and webhook callbacks.
Bulk envelope generation
Upload a CSV of records, get back a ZIP of filled PDFs (or one merged envelope). Built for HR onboarding cohorts and tax-season bursts.
Webhooks & status events
Subscribe to PDF generation events. Get notified when async jobs finish, fields are missing, or quota thresholds approach.
Multi-tenant API keys
Scope keys per organization, environment, and rate limit. Rotate without downtime. Built-in quota tracking and overage billing.
Stop hand-mapping PDF fields.
Upload a template, define your aliases once, then fill from your app's data on every request. Start with a 14-day free trial — cancel anytime.
PDF automation for every industry
Built for teams in HR, legal, healthcare, finance, real estate, government — anywhere a workflow ends in a filled PDF.
New hires complete a single web form. We fill the I-9, W-4, and state withholding forms in parallel and email them ready to sign.
Sync data from your bookkeeping app into our 1040 + Schedule C templates. Generate a full return packet in under 2 seconds per client.
Patient fills out a single intake on the portal. SimplyFill produces the HIPAA, insurance, and consent PDFs in one envelope, signed and ready for the chart.
Template every recurring contract once. Fill from your CRM with one API call when a deal closes. No more manual find-and-replace.
Listing data flows from your MLS integration into the state-specific disclosure packet. Every form correct, every time, in seconds.
Customer KYC data lives in your system. SimplyFill renders every regulator-mandated PDF the second a customer applies — no copy-paste.
Adjusters submit one digital intake. We populate the ACORD form, claimant statement, and policy attachments — ready for the carrier portal.
Replace 12-page paper packets with a single digital application that fans out into every required PDF the agency accepts.
Student information system pushes data straight into the dozens of PDFs each enrollment season demands. Admin time per student drops by 80%.
Pricing that scales with your PDF volume.
Start with a 14-day free trial, then pay only when you ship to production. Overage billed per PDF — never get cut off mid-month.
ProMost popular
$49/mo
For production apps shipping PDFs to real users. 14-day trial.
- 1,000 filled PDFs / month
- +$0.10 per PDF overage
- 1,000 requests / hour
- Unlimited templates
- 5 API keys
- Sync + async generation
- Webhooks
- Email support
14-day free trial. Cancel anytime.
Business
$199/mo
For teams shipping PDFs at scale across multiple environments.
- 10,000 filled PDFs / month
- +$0.05 per PDF overage
- 10,000 requests / hour
- Unlimited templates & AI generations
- 20 API keys
- Bulk envelope generation
- Dev / staging / prod environments
- Priority support
14-day free trial. Cancel anytime.
Enterprise
Custom
Self-host option, SSO, custom DPA, SLA, dedicated support.
- Unlimited PDFs
- 100,000 requests / hour
- Unlimited everything
- SSO / SAML
- Custom DPA & SLA
- Dedicated Slack channel
- Self-host available
Reply within 1 business day.
Frequently asked questions about PDF form filling
19 essential answers. Still stuck? Email us or check the full docs.
Capabilities & supported PDFs2
- What kinds of PDF forms does SimplyFill support?
- Any standard AcroForm PDF — IRS, USCIS, healthcare intake, HR onboarding, legal contracts, real estate disclosures. We auto-detect text fields, checkboxes, radio groups, date fields, and signature fields on upload. XFA-only forms (rare, mostly older government forms) are flattened to AcroForm during ingestion.
- How fast is a single PDF generation?
- Typical sync response is 200–500ms end-to-end for a normal-sized form (under 30 fields, a few pages). For larger forms or bulk runs, switch to async mode and subscribe to a webhook so you are not holding the request open.
Templates & field mapping2
- How does field mapping actually work?
- You upload a template once. SimplyFill detects every PDF field by its raw AcroForm name (often something like topmostSubform[0].Page1[0].f1_02[0]). You then create a mapping that pairs each raw field with a semantic alias of your choice — fullName, dateOfBirth, etc. From that point on, your API requests send the aliases, not the raw names.
- What happens to live API calls if I edit a template?
- Templates are versioned automatically — every edit creates a new version with a changelog. Existing mappings keep pointing at the version they were created against, so production traffic does not break. You promote new versions to staging or prod explicitly.
AI-assisted setup6
- Does SimplyFill use AI to set up my forms?
- Yes. The template-creation wizard uses advanced AI to read each PDF the way a person would and propose a clean, ready-to-use template: human-readable names for every field, a suggested mapping to your data, a detected type per field, and realistic sample data for a preview. It is assistance, not automation — you review and approve every suggestion before anything is published.
- How does the AI know what a field like f1_03[0] actually means?
- It doesn’t guess from the machine name. SimplyFill reads the visible labels and surrounding context the way a person would, rather than relying on the cryptic internal name, and proposes a human-readable alias for each field.
- Can I trust the AI’s suggestions, or is it a black box?
- Every suggestion comes with a confidence score (0–100) and a short evidence note explaining why the AI chose it — for example “nearby label ‘DUE DATE’” or “document context: invoice”. Nothing publishes on its own. You accept, edit, or reject each suggestion, so you spend your time only on the fields the AI is unsure about.
- Is the PDF filling itself done by AI?
- No — and that’s deliberate. AI only accelerates the one-time setup (labeling, mapping, type detection, test data). The engine that actually fills your PDFs is fully deterministic: the same data in always produces the same PDF out. Generation is fast, reliable, and predictable, with no model in the hot path.
- Do I have to use real customer data to test a template?
- No. The AI generates realistic, correctly formatted sample data — valid-format SSNs (XXX-XX-XXXX), EINs, phone numbers, email addresses, ISO dates, and internally consistent city/state/ZIP combinations — and fills a live preview, so you can confirm the form renders correctly without ever exposing real PII in a test run.
- Is AI included on every plan?
- AI features have monthly usage quotas that vary by plan. Free and default tiers include limited or no AI quota; Pro and higher unlock it. The deterministic generation engine works on every plan — AI is the setup accelerator, not a requirement for filling PDFs.
API & integration3
- What's the base URL and authentication scheme?
- All endpoints live under /api/v1/. Authenticate with a bearer token: Authorization: Bearer ***. Each key is scoped to one organization and one environment (dev, staging, or prod).
- Do you offer SDKs?
- Official SDKs for TypeScript/JavaScript, Python, and Go are on the roadmap. Today the REST surface is small enough (~8 endpoints) that most users wrap it themselves in an afternoon.
- Sync vs async — which should I use?
- Sync (default) returns the PDF URL in the response — great for user-facing flows. Async (async_mode: true) returns a task_id (202) and you receive a webhook or poll GET /api/generate/status/{task_id}. Use async for bulk jobs, large PDFs, or anything over ~2 seconds.
Quotas & limits2
- What are the monthly PDF quotas?
- Pro: 1,000 PDFs/month. Business: 10,000. Enterprise: unlimited. Quotas reset on the 1st of every month at 00:00 UTC.
- What happens when I hit my monthly PDF quota?
- Pro allows overage at $0.10/PDF; Business at $0.05/PDF, billed at the end of the period. Warning emails fire at 80% and 95%.
Auth, security & compliance2
- Is SimplyFill HIPAA or SOC 2 compliant?
- SOC 2 Type II is in progress. HIPAA-compliant deployment is available on Enterprise with a signed BAA. For healthcare workflows on Pro or Business today, you can self-host the generation worker.
- Do you store the filled PDFs?
- Yes — generated PDFs are stored for 7 days then automatically deleted. The download_url works the whole time. Storage is encrypted at rest in S3. Enterprise plans support custom retention and bring-your-own-S3.
Pricing & plans2
- What does each plan cost?
- Pro: $49/mo or $490/yr. Business: $199/mo or $1,990/yr. Enterprise: custom — contact sales. All paid plans start with a 14-day free trial. Annual billing gives you 2 months free.
- Is there a free trial of paid plans?
- Yes — Pro and Business both come with a 14-day trial. A credit card is required to start, and the plan auto-converts to paid when the trial ends; cancel anytime before then and you won’t be charged. Enterprise trials are custom; contact sales.