Runs locally · Zero uploads

PDF Fill Form

Fill AcroForm fields, optionally flatten to lock them in.

How it works

Fill AcroForm PDF fields without uploading the document. Common workflow: tax forms, HR onboarding, e-signature prep. Provide field values as a JSON map of field name to value (string for text fields, boolean for checkboxes). Optionally flatten the form so the values become permanent.

Verify it yourself. Open DevTools → Network → run a conversion. The only requests you'll see are the page assets — your file never leaves this tab.

FAQ

How do I know what field names to use?

Open the PDF in Acrobat or the Bytario PDF Info tool to see the field list. Field names are case-sensitive.

What about XFA forms?

V1 supports AcroForm only — that covers about 95% of fillable PDFs in the wild. XFA (used by some legacy government forms) is not supported.

When should I flatten?

Flatten when sending the final document to someone who should not be able to edit the values. Skip flatten if the recipient needs to add more fields or change values.