How do I generate form fields from a PDF with AI?

Last updated: June 5, 2026

Upload a PDF, pick an AI model, and let Onboarded scaffold the form pages and fields for you — then edit, save, and continue to PDF mapping.

Before you start

  • You have permission to create forms on your account.

  • You have the source PDF on hand. The cleaner the PDF (text, not a scan), the better the AI output.

  • You understand how form pages and assignees work (see 📄 Understanding forms).

Steps

The flow has three phases: pick a model and upload the PDF, review and refine the generated fields, then save before you leave the editor.

Pick a model and upload the PDF

  1. Go to Forms in the left navigation and click New Form.

  2. Choose Create a New Form, then on the next screen choose the option to generate fields from a PDF.

  3. Pick an AI model in the AI Model dropdown.

    • Gemini 2.5 Flash Lite is the default — fast, good for short or simple PDFs.

    • Claude Sonnet 4.5 is the better choice for long, dense, or layout-heavy PDFs (multi-section state tax forms, hardship withdrawal packets, anything with stacked sub-questions). It's slower but more accurate.

  4. Drop the PDF into the chat window. Onboarded streams back a suggested form name, description, and pages of fields.

  5. Confirm or edit the form name and description, then click Create. The AI editor opens with the generated pages and fields.

    You should see one or more pages in the left sidebar, each tagged with an assignee badge (employee or employer) inferred from context.

Refine the fields with explicit prompts

  1. Review each page in the outline. The AI groups related questions automatically — for example, consolidating "First name, Middle initial, Last name" into one logical block. Reorder, rename, or split fields as needed.

  2. Use the AI chat inside the editor to make targeted changes instead of editing field by field. Explicit prompts work best — give the AI a clear instruction and the context it needs.

    • Vague: "Clean this up."

    • Explicit: "Match the PDF using only the fields already on the form — don't add new ones."

    • Explicit: "Move the direct deposit section to its own page and set the assignee to employee."

Save before switching tabs. Unsaved field changes in the AI editor can be lost if you navigate away. Click Save after every batch of edits — especially before opening the PDF mapping view or the form preview.

  1. Adjust assignees on a per-page basis if the AI guessed wrong in the Visual Builder. Click into a page in the sidebar and update its assignee badge.

Verify

Your generated form is ready when:

  • Every field in the PDF has a matching field in the form (or an explicit reason it doesn't, like a system-populated value).

  • Pages are split by assignee — fields the employee completes are on one page, fields the employer completes are on another.

  • The form name and description make sense to someone who didn't build it.

If the generation looks wrong (missing fields, duplicates, fields drifting onto the wrong page), re-run with Claude Sonnet 4.5 and a more explicit description.

The next step is to drag the form fields onto the PDF so submissions flow back into the source document. See 📄 How do I swap the PDF on a published form without losing my mappings? if you're updating an existing form's PDF source.

Troubleshooting

AI generates fewer fields than expected on a long PDF

On very long PDFs, the AI may stop partway through — generating 5 of 10 work history entries, for example, or missing the final section entirely. This is a context-length limitation, not a configuration problem. Try these steps in order:

  1. Fix the YAML with an external AI. In the form editor, switch to the Code tab to view the raw YAML. Copy it, paste it into an AI assistant outside Onboarded, and describe what's missing — for example, "Section 6 should have 10 work history entries but only has 5; please add the remaining 5 using the same structure." Paste the corrected YAML back into the Code tab and save.

  2. Use the in-product Fix Errors button. If the YAML has a validation error, switch to the Chat tab in the form editor. When the editor detects an error, a Fix Errors button appears — click it to let the in-product AI attempt a repair.

  3. Add the missing fields manually or use a Repeatable Group. If both AI approaches fail, add the remaining fields by hand in the Visual Builder. For sections with many identical repeating slots (work history, references, education), a 📄 How do I use a repeatable group to collect multiple entries on a form? is often cleaner than stacking duplicate conditional fields — one group definition with a max-instances limit, mapped once per slot with bracket index notation.

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